Exhaust device, internal combustion engine exhaust gas flow system, and method of improving engine efficiency and reducing air pollutant emissions

Abstract

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Description

FIELD OF THE INVENTION The invention relates generally to an exhaust device. More particularly, the present invention relates to an exhaust device for use in an exhaust system of an internal combustion engine. The invention also relates to a method of use of the exhaust device in an exhaust system for improving engine efficiency and / or reducing air pollutant emissions. BACKGROUND OF THE INVENTION Internal combustion engines operate by combusting a fuel-oxidiser mixture within a combustion chamber to generate power. The combustion process produces high-temperature, high-pressure exhaust gases that expand and that directly apply a force to move a piston component of the engine. Once the combustion cycle is complete, the exhaust gases are then expelled from the combustion chamber and are replaced with a fuel-oxidiser mixture, preparing the engine for the next combustion cycle. The process of expelling exhaust gases and replacing them with a fuel-oxidiser mixture is known as scavenging. Efficient scavenging is crucial for maintaining optimal engine performance. If residual exhaust gases remain in the combustion chamber, they dilute the incoming fuel-oxidiser charge, reduce the efficiency of combustion, and can lead to incomplete burning of the fuel, ultimately decreasing power output and increasing emissions. In naturally aspirated engines, scavenging is primarily driven by the pressure difference between the combustion chamber and the exhaust system. When the exhaust port of the combustion chamber is opened, high-pressure exhaust gases flow into the exhaust manifold, which directs them away from the engine and eventually releases them via the exhaust system into the atmosphere. However, the engine must overcome resistance within the exhaust system, commonly referred to as backpressure, in order to completely discharge exhaust gases from within the combustion chamber. High backpressure can hinder the evacuation of exhaust gases, leading to incomplete scavenging and suboptimal engine performance. 2026202912   17 Apr 2026 To improve scavenging efficiency, exhaust systems are often modified to optimise the flow of exhaust gases. Depending on the engine design and operating cycle, this may involve the use of expansion chambers, extractors, or headers to enhance the velocity of the exhaust gas away from the combustion chamber as well as reduce backpressure. These modifications help improve the filling of the combustion chamber with the next intake charge of fuel-oxidiser mixture, thereby enhancing combustion efficiency and overall engine performance. Forced induction (turbocharging or supercharging) to increase the intake charge pressure can improve scavenging, in addition to variable valve timing systems, which adjust exhaust and intake valve timing to optimise gas exchange dynamics. While these approaches improve scavenging under specific conditions, they are often limited in effectiveness across the full operating range of an engine, particularly under transient loads or varying speeds. Water injection into the exhaust manifold of a two-stroke diesel engine has been explored as a technique to improve engine efficiency, and reduce nitrogen oxide (‘NOx’) emissions. It is thought that the injection of water by this approach utilises the enthalpy of the exhaust gases to evaporate the water before combustion, thereby reducing particulate matter and NOx emissions without significantly lowering combustion temperatures. It has also been found that the injection of water into the exhaust manifold can increase cylinder pressure. However, these existing water injection systems face several challenges, which include condensation and accumulation of liquid water in the exhaust system and combustion chamber, uncontrolled water distribution in the exhaust system, interference with engine performance, and durability and maintenance issues. It is therefore desired to address or ameliorate one or more shortcomings or disadvantages associated with existing exhaust water injection systems, or to at least provide a useful alternative thereto. Any discussion of documents, acts, materials, devices, articles or the like which has been included in the present specification is not to be taken as an admission that any or all of these matters form part of the prior art base or were common general knowledge in the field relevant to the present disclosure as it existed before the priority date of each claim in this application. SUMMARY OF THE INVENTION In a first aspect of the invention, there is provided an exhaust device for an internal combustion engine exhaust gas flow system, said exhaust device comprising: 2026202912   17 Apr 2026 an expansive cone portion adapted to receive exhaust gas produced by combustion within an internal combustion engine; an injection chamber portion fluidly coupled to the expansive cone portion for receiving exhaust gas from the expansive cone portion and configured to allow for turbulent mixing of exhaust gas within the chamber portion; and a contractive cone portion fluidly coupled to the injection chamber portion to receive exhaust gas from the injection chamber portion, the contractive cone portion being configured to direct exhaust gas flow downstream, wherein the expansive cone, injection chamber, or contractive cone portions include at least one fluid inlet port for introducing a conditioning fluid into a flow path of exhaust gas within the injection chamber portion, so that the conditioning fluid mixes with said exhaust gas. In a second aspect of the invention, there is provided an exhaust device for an internal combustion engine exhaust gas flow system, said exhaust device comprising: an expansive cone portion adapted to receive exhaust gas produced by combustion within an internal combustion engine; an injection chamber portion fluidly coupled to the expansive cone portion for receiving exhaust gas from the expansive cone portion; and a contractive cone portion fluidly coupled to the injection chamber portion to receive exhaust gas from the injection chamber portion, the contractive cone portion being configured to direct exhaust gas flow downstream, wherein the injection chamber portion is configured to allow a conditioning fluid into a flow path of exhaust gas within the injection chamber portion, so that the conditioning fluid vaporises and mixes with said exhaust gas. In a third aspect of the invention, there is provided an internal combustion engine exhaust gas flow system, said exhaust gas flow system comprising: an exhaust device according to the first or second aspect; a reservoir for housing a conditioning fluid; and 2026202912   17 Apr 2026 a dosing device configured to controllably introduce a conditioning fluid from the reservoir into a flow path of an exhaust gas within the injection chamber portion of the exhaust device. In a fourth aspect of the invention, there is provided an internal combustion engine exhaust gas flow system, said exhaust gas flow system comprising: an exhaust device according to the first or second aspect; a reservoir for housing a conditioning fluid; and a dosing device configured to dispense a conditioning fluid from the reservoir into at least one fluid inlet port disposed in either the expansive cone, injection chamber, or contractive cone portions, so that the conditioning fluid is introduced into a flow path of an exhaust gas in the injection chamber portion and mixes with said exhaust gas. In a fifth aspect of the invention, there is provided an internal combustion engine exhaust gas flow system, said exhaust gas flow system comprising: an exhaust device according to the first or second aspect; a reservoir for housing a conditioning fluid; and a dosing device configured to dispense a conditioning fluid from the reservoir into a flow path of an exhaust gas in the injection chamber portion, so that the conditioning fluid vapourises and mixes with said exhaust gas. In a sixth aspect of the invention, the invention provides a method of improving engine efficiency and / or reducing air pollutant emissions, the method including: providing a conditioning fluid; and introducing the conditioning fluid into a flow path of an exhaust gas in an injection chamber of an exhaust device according to the first or second aspect. Preferably, the engine is a four-stroke internal combustion engine. More preferably, the engine is a four-stroke petrol engine. 2026202912   17 Apr 2026 In a seventh aspect of the invention, the invention provides a method of improving engine efficiency and / or reducing air pollutant emissions, the method including: providing a conditioning fluid; vaporising the conditioning fluid to provide a conditioning vapour; and introducing the conditioning vapour into a flow path of an exhaust gas in an injection chamber of an exhaust device according to the first or second aspect, so that the conditioning fluid vapour mixes with said exhaust gas. Preferably, the engine is a four-stroke internal combustion engine. More preferably, the engine is a four-stroke petrol engine. In an eighth aspect of the invention, there is provided an exhaust device for an internal combustion engine exhaust gas flow system, the exhaust device comprising: an inlet portion adapted to receive exhaust gas produced by combustion within an internal combustion engine, the inlet portion having a diameter that is greater at a downstream location than at an upstream location of exhaust gas flow; an injection chamber portion fluidly coupled to the inlet portion for receiving exhaust gas from the inlet portion and configured to allow for turbulent mixing of exhaust gas within the injection chamber portion; an outlet portion fluidly coupled to the injection chamber portion to receive exhaust gas from the injection chamber portion, the outlet portion having a diameter that is greater at a upstream location than at an downstream location of exhaust gas flow, wherein the inlet portion, injection chamber portion, or outlet portion include at least one fluid inlet port for introducing a conditioning fluid into a flow path of exhaust gas within the injection chamber portion, so that the conditioning fluid mixes with said exhaust gas. Without wishing to be bound by theory, it is believed that by mixing a conditioning fluid or a conditioning vapour with an exhaust gas from an internal combustion engine in an injection chamber disposed between an expansive cone portion and a contractive cone portion, improves engine efficiency and / or reduces air pollutant emissions. It is further believed that the injection chamber, having a larger internal bore than exhaust header pipes and other portions of the exhaust system, promotes expansion of the exhaust gas and enhanced turbulent mixing within 2026202912   17 Apr 2026 the injection chamber, thereby improving interaction between the exhaust gas and the conditioning fluid or conditioning vapour prior to downstream flow through the contractive cone portion. Alternatively, an object of the present invention to overcome, or at least substantially ameliorate, the disadvantages and shortcomings of the prior art. Further aspects and advantages of the present invention, which should be considered in all its novel aspects, will become apparent to those skilled in the art upon reading of the following description which provides at least one example of a practical application of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments of the technology will be described below by way of example only, and without intending to be limiting, with reference to the following drawings, in which: Figure 1 is a first schematic illustration of an internal combustion engine and exhaust having an exhaust device according to the invention. Figure 2 is a second schematic illustration of an internal combustion engine and exhaust having an exhaust device according to the invention. Figure 3 is a graphical representation of the engine power output when using an unmodified factory exhaust and an exhaust system including the exhaust device according to the present invention. Figure 4 is a graphical representation of the engine torque when using an unmodified factory exhaust and an exhaust system with the exhaust device according to the present invention. Figure 5 is a graphical representation of potential power benefits using the device or method of the invention. Figure 6 is a graphical representation of potential torque benefits using the device or method of the invention. DETAILED DESCRIPTION OF THE INVENTION In a first aspect of the invention, there is provided an exhaust device (1) for an internal combustion engine exhaust gas flow system, said exhaust device comprising: an expansive cone portion (2) 2026202912   17 Apr 2026 adapted to receive an exhaust gas (3) produced by combustion within an internal combustion engine (4); an injection chamber portion (5) fluidly coupled to the expansive cone portion (2) for receiving exhaust gas (3) from the expansive cone portion (2) and configured to allow turbulent mixing of exhaust gas within the chamber portion; and a contractive cone portion (6) fluidly coupled to the injection chamber portion (5) to receive exhaust gas from the injection chamber portion, the contractive cone portion (6) being configured to direct exhaust gas (3) flow downstream, wherein the expansive cone (2), injection chamber (5), or contractive cone (6) portions include at least one fluid inlet port (7) for introducing a conditioning fluid (8) into a flow path of exhaust gas (3) within the injection chamber portion (5), so that the conditioning fluid (8) mixes with said exhaust gas (3). As used herein, the term ‘conditioning fluid’ refers to a liquid or vapourisable medium introduced into exhaust gas to modify its thermodynamic, chemical, or flow characteristics. In some examples the conditioning fluid is water. In other examples the conditioning fluid is methanol or ethanol. In yet further examples the conditioning fluid is any liquid or vapourisable medium that when introduced into exhaust gas modifies its thermodynamic, chemical, or flow characteristics. In a second aspect of the invention, there is provided an exhaust device (1) for an internal combustion engine exhaust gas flow system, said exhaust device comprising: an expansive cone portion (2) adapted to receive an exhaust gas (3) produced by combustion within an internal combustion engine (4); an injection chamber portion (5) fluidly coupled to the expansive cone portion (2) for receiving exhaust gas (3) from the expansive cone portion (2); and a contractive cone portion (6) fluidly coupled to the injection chamber portion (5) to receive exhaust gas from the injection chamber portion, the contractive cone portion (6) being configured to direct exhaust gas (3) flow downstream, wherein the injection chamber portion (5) is configured to allow a conditioning fluid (8) into a flow path of exhaust gas (3) within the injection chamber portion (5), so that the conditioning fluid (8) vaporises and mixes with said exhaust gas (3). In a third aspect of the invention, there is provided an internal combustion engine exhaust gas flow system, said exhaust gas flow system comprising: an exhaust device (1) comprising an expansive cone portion (2), injection chamber portion (5) and a contractive cone portion (6); a reservoir (9) for housing a conditioning fluid (8); and a dosing device (10) configured to controllably introduce a conditioning fluid (8) from the reservoir (9) into a flow path of an exhaust gas (3) within the injection chamber portion (5) of the exhaust device (1). In a fourth aspect of the invention, there is provided an internal combustion engine exhaust gas flow system, said exhaust gas flow system comprising: an exhaust device (1) comprising an 2026202912   17 Apr 2026 expansive cone portion (2), injection chamber portion (5) and a contractive cone portion (6); a reservoir (9) for housing a conditioning fluid (8); and a dosing device (10) configured to dispense a conditioning fluid (8) from the reservoir (9) into at least one fluid inlet port (7) disposed in either the expansive cone (2), injection chamber (5), or contractive cone (6) portions, so that the conditioning fluid (8) is introduced into a flow path of an exhaust gas (3) in the injection chamber portion (5), so that the conditioning fluid (8) mixes with said exhaust gas (3). In a fifth aspect of the invention, there is provided an internal combustion engine exhaust gas flow system, said exhaust gas flow system comprising: an exhaust device (1) comprising an expansive cone portion (2), injection chamber portion (5) and a contractive cone portion (6); a reservoir (9) for housing a conditioning fluid (8); and a dosing device (10) configured to dispense a conditioning fluid (8) from the reservoir (9) into a flow path of an exhaust gas (3) in the injection chamber portion (5), so that the conditioning fluid (8) vapourises and mixes with said exhaust gas (3). In a sixth aspect of the invention, the invention provides a method of improving engine efficiency and / or reducing air pollutant emissions, the method including: providing a conditioning fluid (8); and introducing the conditioning fluid (8) into a flow path of an exhaust gas (3) in an injection chamber (5) of an exhaust device (1). In a seventh aspect of the invention, the invention provides a method of improving engine efficiency and / or reducing air pollutant emissions, the method including: providing a conditioning fluid (8); vaporising the conditioning fluid (8) to provide a conditioning vapour; and introducing the conditioning vapour into a flow path of an exhaust gas (3) in an injection chamber (5), so that the conditioning fluid vapour mixes with the exhaust gas (3). The expansive cone portion may assume a variety of profiles depending on the intended application, and is preferably a conical frustum. Suitable cone profiles include, but are not limited to, truncated right circular cones, and oblique truncated cones. The projected or virtual apex angle of the expansive cone may vary between approximately 10° to 80°, and the cone may be oriented with its projected or virtual apex directed upward, downward, or laterally oriented, as desired. The projected or virtual apex angle of the expansive cone may be in the range of 10° to 80°, 10° to 70°, 20° to 70°, 30° to 70°, 40° to 70°, 50° to 70°, 10° to 60°, 20° to 60°, 30° to 60°, 40° to 60°, 50° to 60°, 10° to 50°, 20° to 50°, 30° to 50°, 40° to 50°, 10° to 40°, 20° to 40°, 30° to 40°, 10° to 30°, 20° to 30°, or 10° to 20°. In some embodiments, the side face (or side wall) of the expansive cone portion may deviate from a straight taper and instead exhibit a concave or convex curvature, thereby having a non-linear profile between the virtual small and large base faces. A concavely curved side face may facilitate structural strength and modulate the flow of an exhaust gas. A 2026202912   17 Apr 2026 convex profile may facilitate the movement of exhaust gas and / or facilitate the mixing of a conditioning vapour with an exhaust gas. In certain embodiments, the small and large virtual base faces of the expansive cone portion may be circular, elliptical or polygonal or otherwise noncircular, to accommodate specific interfacing or mounting requirements in an exhaust system. The interior side face of the expansive cone portion may be smooth, contoured, fluted, or stepped to provide specific aerodynamic, aesthetic, or mechanical characteristics. In some embodiments the interior side face of the expansive cone portion may be smooth, contoured, fluted, or stepped to influence flow dynamics, reduce back pressure, or enhance mixing of an exhaust gas as it passes through the interior of the expansive cone portion. The exterior side face of the expansive cone portion may be independent of the interior side face and be smooth, fluted, or stepped to provide specific aerodynamic, aesthetic, or mechanical characteristics. Dimensional parameters such as the small and large virtual base face diameters, axial height, wall thickness, and taper ratio may vary depending on the desired aerodynamic effect on exhaust gas flow, and these parameters may be uniform or non-uniform along the length of the expansive cone. In use, exhaust gases flow through the expansive cone portion from a first, small virtual base face toward the second, large virtual base face, such that the direction of flow generally follows the taper of the cone from a narrower inlet region to a broader outlet region. The term "virtual base face" as used herein refers to the notional planar cross-sectional area defined at the narrow and wide ends of the expansive cone portion. The conical geometry serves to facilitate expansion, diffusion, or directional control of the exhaust gases as they pass through the interior of the expansive cone portion. Flow from the small virtual base face to the large virtual base face may occur under forced or passive conditions and may be laminar, transitional, or turbulent depending on the exhaust manifold and / or exhaust system configuration. The expansive cone portion may have a diameter that is greater at a downstream location than at an upstream location of exhaust gas flow. The injection chamber portion may exhibit a range of structural and geometric configurations suitable for the intended application. The injection chamber may be straight, curved, bent, coiled, or segmented, and may extend along a linear, curved, or helical path. The cross-sectional shape of the injection chamber may be circular, oval, elliptical, polygonal (e.g. hexagonal, octagonal), or irregular, and may be uniform or variable along its axial length. In some embodiments, the injection chamber may include regions of taper, flare, or stepped diameters to accommodate interfacing with other components or to regulate exhaust gas flow or facilitate mixing of a conditioning fluid and / or a conditioning vapour with an exhaust gas. The sidewall of the injection chamber may be of constant or varying thickness, and the internal side wall may be smooth or 2026202912   17 Apr 2026 textured, or include internal surface features such as ridges, threads, slots, or corrugations to modulate exhaust gas flow or facilitate mixing of a conditioning fluid and / or a conditioning vapour with an exhaust gas. The injection chamber may include one or more integrated ports, valves, or connectors. The injection chamber may include straight segments, angled junctions, or branching configurations such as Y-shaped or T-shaped arrangements. In certain embodiments, the injection chamber may be integrally formed with the expansive cone and / or contracting cone to provide a discrete, attachable exhaust device as an aftermarket part. In other embodiments the injection chamber together with the expansive cone and contracting cone are not integrally formed. The contractive cone portion may assume a variety of profiles depending on the intended application, and is preferably a conical frustum. Suitable cone profiles include, but are not limited to, truncated right circular cones, and oblique truncated cones. The projected or virtual apex angle of the contracting cone portion may vary between approximately 10° to 80°, and the cone may be oriented with its projected or virtual apex directed upward, downward, or laterally oriented, as desired. The projected or virtual apex angle of the contracting cone portion may be in the range of 10° to 80°, 10° to 70°, 20° to 70°, 30° to 70°, 40° to 70°, 50° to 70°, 10° to 60°, 20° to 60°, 30° to 60°, 40° to 60°, 50° to 60°, 10° to 50°, 20° to 50°, 30° to 50°, 40° to 50°, 10° to 40°, 20° to 40°, 30° to 40°, 10° to 30°, 20° to 30°, or 10° to 20°. Preferably, the projected or virtual apex angle of the contractive cone portion is less than the projected or virtual apex angle of the expanding cone, such that the taper of the contractive cone portion is more gradual than that of the expanding cone portion. This configuration may assist in maintaining exhaust gas flow velocity, and / or promote efficient mixing with a conditioning fluid or conditioning vapour in the injection chamber. In certain embodiments, the contractive cone portion may have a projected or virtual apex angle of between 10° and 40°, or between 15° and 35°, or between 20° and 30°, while the expansive cone portion may have a projected apex angle of between 30° and 80°, or between 40° and 70°, or between 50° and 65°. In some embodiments, the contractive cone portion may have an apex angle in the range of 10° to 20°, 15° to 25°, or 20° to 30°, and the expansive cone portion may have an apex angle in the range of 40° to 60°, 45° to 65°, or 50° to 70°. The relative difference in projected or virtual apex angles may be selected based on desired exhaust gas flow characteristics and spatial constraints if the exhaust device is provided as an aftermarket component. In some embodiments, the side face of the contractive cone portion may deviate from a straight taper and instead exhibit a concave or convex curvature, thereby having a non-linear profile between the virtual base faces. A concavely curved sidewall may provide facilitate structural 2026202912   17 Apr 2026 strength and modulate the flow of exhaust gas. A convex profile may facilitate the movement of exhaust gas and / or facilitate the mixing of a conditioning vapour with an exhaust gas. In certain embodiments, small and large virtual base faces of the contractive cone portion may be circular, elliptical or polygonal or otherwise non-circular, to accommodate specific interfacing or mounting requirements in an exhaust system. The interior side face of the contractive cone portion may be smooth, fluted, contoured, or stepped to provide specific aerodynamic, aesthetic, or mechanical characteristics. In some embodiments the interior side face of the contractive cone portion may be smooth, contoured, fluted, or stepped to influence flow dynamics, reduce back pressure, or enhance mixing of an exhaust gas as it passes through the interior of the contractive cone portion. In some embodiments, the interior surface of the contractive cone portion may include flowdirecting features to reduce turbulence, modulate back pressure, or enhance mixing or propulsion effects. The exterior curved side face of the contractive cone portion may be smooth, fluted, or stepped to provide specific aerodynamic, aesthetic, or mechanical characteristics. Dimensional parameters such as small and large virtual base face diameters, axial height, wall thickness, and taper ratio may vary depending on the desired aerodynamic effect on exhaust gas flow, and these parameters may be uniform or non-uniform along the length of the contractive cone portion. In use, exhaust gases flow through the contractive cone portion from a first, large virtual base face toward a second, small virtual base face, such that the direction of exhaust gas flow is generally from a broader inlet region to a narrower outlet region along the taper of the contractive cone portion. The term "virtual base face" as used herein refers to an imaginary planar crosssection at each axial end of the contractive cone portion, representing the effective flow boundaries. The converging geometry of the cone may function to compress, accelerate, or concentrate the exhaust gases as they move toward the small virtual base face. In some embodiments, the geometry of the contractive cone portion is configured to influence exhaust gas pressure and velocity after the exhaust gas exits the injection chamber. In some examples the geometry of the contractive cone portion is configured to increase exhaust gas pressure after the exhaust gas exits the injection chamber. Flow from the large virtual base face to the small virtual base face may occur under naturally aspirated or forced-flow conditions and may be configured to promote efficient evacuation, directional control, or thermodynamic optimisation of exhaust gases within the system. The contractive cone portion may have a diameter that is greater at a upstream location than at a downstream location of exhaust gas flow. In certain embodiments, the expansive cone, injection chamber and / or the contractive cone portions include at least one fluid inlet port configured for the introduction of a conditioning fluid. The fluid inlet port may be positioned along the sidewall of the expansive cone, injection chamber 2026202912   17 Apr 2026 and / or the contractive cone portions, or at transitional junction between either the expansive cone and injection chamber, or the injection chamber and contractive cone portions. The fluid inlet port may be in fluid communication with a dosing device configured to dispense a conditioning fluid from a reservoir into a flow path of an exhaust gas in the injection chamber. The fluid inlet port may be configured to accommodate a conditioning fluid and / or a conditioning vapour. In some embodiments, multiple fluid inlet ports may be provided at spaced-apart locations to achieve distributed and / or directional injection of a conditioning fluid or conditioning vapour. The fluid injection port may be configured to accommodate valves, nozzles, or flow restrictors to regulate the rate, pattern, or pressure of entry of a conditioning fluid and / or a conditioning vapour. The fluid inlet port is adapted to receive a spray nozzle for directing the conditioning fluid into the interior of the injection chamber. The spray nozzle may be fixed or removable, and may be configured to deliver the conditioning fluid in a controlled spray pattern to enhance exhaust gas flow dynamics, and / or facilitate mixing of the conditioning fluid and / or conditioning vapour with the exhaust gas. Suitable spray nozzles may include full-cone, hollow-cone, or flat spray nozzles. In some embodiments, the spray nozzle is a flat spray nozzle configured to produce a fan-type spray pattern having tapered edges, thereby generating a broad, sheet-like distribution of conditioning fluid that diminishes gradually toward the periphery. The direction of spray from the spray nozzle may be oriented transverse, parallel, or obliquely relative to the primary exhaust gas flow axis, depending on the desired coverage within the exhaust device and / or exhaust gas conditioning effect. The spray nozzle selected may be based upon an internal profile of at least one of the expansive cone, injection chamber, or contractive cone portions, so as to provide for efficient gasphase contact and mixing with the conditioning fluid and / or conditioning fluid vapour. In some embodiments, the spray nozzle selected may be based upon the exhaust gas characteristics, so as to provide for efficient vapourisation of the conditioning fluid. In some embodiments, the exhaust device further comprises a spray nozzle received by the fluid inlet port, for directing the conditioning fluid into the interior of the injection chamber portion. The spray nozzle may be selected or configured to operate within a pressure range of 5 to 500 psi, 50 psi to 400 psi, or preferably 100 psi to 200 psi, depending on the desired atomisation and dispersion characteristics of the conditioning fluid. The droplet size produced by the spray nozzle may be in the range of 10 pm to 1000 pm, 20 pm to 500 pm, or preferably 30 pm to 200 pm. Those skilled in the art can modulate the droplet size as desired based on the conditioning fluid used by adjusting the pressure, and / or spray nozzle type. 2026202912   17 Apr 2026 The conditioning fluid may be introduced to reduce the temperature of exhaust gases, protect adjacent components from heat exposure, or control thermal gradients within the structure. The conditioning fluid may be selected from the group consisting of: water, methanol, ethanol, isopropanol, butanol, propylene carbonate, glycerol and any combination thereof. The conditioning fluid may preferably be an aqueous solution of propylene carbonate, and / or glycerol. More preferably, the conditioning fluid is water. Even more preferably, the conditioning fluid is distilled water. By way of a further example, the conditioning fluid is water having a resistivity of approximately 18.2Q cm at 25°C and having a total organic carbon of <5 ppb. In other embodiments, the conditioning fluid may be water which has been doped with urea. Exhaust gases generated from combustion in an internal combustion engine, are directed from one or more of the engine’s cylinders into an exhaust manifold, which serves as a conduit to collect and channel the exhaust gases from the one or more cylinders. The exhaust manifold is typically a cast or welded structure that connects the individual exhaust ports of the engine to a single or multiple outlet passages. Once the exhaust gases enter the manifold from one or more of the individual exhaust ports, they are conveyed and are generally converged into a single exhaust pipe, which typically has a larger diameter than the manifold, allowing for the efficient expulsion of the gases from the engine. Typically, the gas flow path distance from each individual exhaust ports of the engine and the point of convergence in the manifold varies. When the flow path distance differs, the exhaust gases from each cylinder will experience different travel times and therefore may have different average temperatures and pressures before reaching the exhaust manifold's convergence point. These differences in the characteristics of the exhaust gases can result in suboptimal exhaust scavenging, where the pulses of exhaust gases from one cylinder may interfere with the pulses from others, reducing the overall efficiency of the exhaust gas evacuation. To counteract this, the exhaust manifold may be modified or configured so the gas flow path distance from each individual exhaust ports of the engine and the point of convergence in the manifold is identical. It is believed with the present invention, that engine performance and / or engine efficiency is improved when an exhaust manifold is selected that provide a gas flow path distance from each individual exhaust ports of the engine and the point of convergence in the manifold which is substantially identical, or identical. After the exhaust gases exit the exhaust manifold, they may be directed through one or more exhaust devices according to the present invention that are fitted downstream of the exhaust manifold to condition the exhaust gas. The exhaust device according to the present invention may be used in addition to existing components of an exhaust system, which include and are not limited to catalytic converters, mufflers, resonators, particulate filters by way of an example only. 2026202912   17 Apr 2026 The exhaust device according to the present invention may be connected to the exhaust manifold through a flanged or welded joint, ensuring a secure and sealed interface that allows the exhaust gases to flow smoothly through the system. A reservoir for housing a conditioning fluid may be provided in an internal combustion engine exhaust gas flow system according to the invention, to provide for the storage of the conditioning fluid before it is transferred to condition the exhaust gas within the injection chamber. The reservoir is typically positioned in close proximity to exhaust device and is designed to hold a sufficient volume of conditioning fluid based on the average runtime of the internal combustion engine. The reservoir may be constructed from materials resistant to corrosion, pressure, and thermal stress, such as metals (e.g., aluminium or stainless steel) or durable plastics (e.g., polypropylene or polyethylene). The reservoir may be equipped with an accessible inlet port for adding conditioning fluid into the reservoir, and includes an outlet port to transfer conditioning fluid from the reservoir to the exhaust device to condition the exhaust gas within the injection chamber. In certain embodiments, the reservoir may include a level sensor to monitor fluid volume, and optionally a pressure relief valve to prevent over-pressurisation. The reservoir may be designed with one or more baffles or internal structures to prevent and / or reduce fluid sloshing, and / or provide a consistent supply of conditioning fluid to the exhaust device. A dosing device configured to controllably introduce a conditioning fluid from the reservoir may be provided in an internal combustion engine exhaust gas flow system according to the invention. The dosing device may be configured to controllably introduce a conditioning fluid from the reservoir into a flow path of an exhaust gas within the injection chamber of the exhaust device. The dosing device may controllably introduce a conditioning fluid into the expansive cone, injection chamber, and / or contractive cone of the exhaust device, to ensure precise and regulated delivery of the conditioning fluid into the flow path of an exhaust gas within the injection chamber of the exhaust device. The dosing device may be considered to include a flow control mechanism and an actuator for controlling the flow control mechanism. The flow control mechanism may be a valve, such as a solenoid valve, needle valve, or diaphragm valve, to regulate the amount of conditioning fluid allowed to pass from the reservoir to the exhaust device based on the desired dosage. The dosing device may be equipped with a sensor or metering system to monitor and measure the conditioning fluid flow rate, pressure, or volume, to ensure that a desired amount of conditioning fluid is delivered. The flow control mechanism may be electronically or mechanically controlled by an actuator, allowing for dynamic adjustment of the dosing rate in response to system conditions such as, an onboard diagnostics system that monitors engine performance of an internal combustion engine interfaced with the exhaust device. This may include monitoring 2026202912   17 Apr 2026 how many times the internal combustion engine's crankshaft rotates in one minute. In some embodiments, the dosing device may incorporate a feedback control system, where at least one sensor provides real-time data to a controller, which modulates the actuator to fine-tune conditioning fluid introduction based on the operating parameters of the engine or the characteristics of the exhaust gas. In some embodiments, the controller executes a control routine comprising: detecting engine speed; comparing to a threshold; activating the dosing device. In some examples, the controller may receive input from one or more sensors and provide control over an actuator operatively coupled to the flow control mechanism. The controller may be configured to control the actuator to adjust the position or state of the flow control mechanism in accordance with one or more predefined parameters or dosing profiles. The controller may include a processor and memory for executing control algorithms. The dosing device may ensure that the conditioning fluid is introduced in a precise manner, preventing over- or under-dosing, so as to improve the overall efficiency and performance of the engine and / or reduce air pollutant emissions. In some embodiments, the at least one sensor may monitor the exhaust gas temperature, water vapour, and / or pressure, for modulating a pump and / or one of more flow control mechanisms, as necessary to maintain the desired exhaust gas conditioning. In certain embodiments, the conditioning fluid in the reservoir is carefully metered, pressurised, before it is introduced into the injection chamber to ensure precise conditioning of the exhaust gas. The conditioning fluid may be stored in the reservoir under standard temperature and pressures before it is transferred and / or pressurised by a pump to provide a consistent flow rate and pressure suitable for effective delivery of the conditioning fluid to the exhaust device. The pump may be selected from a positive displacement pump, centrifugal pump, or diaphragm pump. The pump may be driven mechanically, electrically, or hydraulically, depending on the conditioning fluid requirements to condition the exhaust gas and the system the exhaust is to be used in. In some embodiments the operation of the pump is controlled by a switch. The switch may be mechanically or electronically actuated. The switch may respond to a user input or to a sensed condition such as a decrease in conditioning fluid pressure at a spray nozzle. In preferred embodiments, the switch is an electronic pressure switch. In some embodiments that switch may be controlled by a controller. After the conditioning fluid is pressurised, the conditioning fluid may be directed through one or more flow control mechanisms, such as valves, regulators, or flow meters, use to modulate the flow rate of the conditioning fluid to at least one spray nozzle. In some embodiments, the one 2026202912   17 Apr 2026 more spray nozzles may be heated to facilitate the vaporisation of the conditioning fluid. The one or more flow control mechanisms may optionally include pressure regulators that maintain the conditioning fluid at a predetermined pressure, typically in the range of 5 to 500 psi, or more depending on the system design. By maintaining the conditioning fluid at a predetermined pressure this may provide consistent atomisation when the conditioning fluid exits the spray nozzle. In some embodiments of the invention, the dosing device introduces conditioning fluid into the injection chamber at a time when an open position of an inlet valve overlaps with an open position of an exhaust valve of the internal combustion engine. In some embodiments of the invention, a conditioning fluid is introduced into the injection chamber at a time when a rotational speed of the engine is above a predetermined value. In some embodiments, the invention delivers a conditioning fluid is introduced into the injection chamber at a time when a desired inlet volume of the fuel-oxidiser mixture is above a predetermined value. A desired inlet volume of the fuel oxidiser mixture can be inferred from a position of the engine throttle or position of a component of a carburettor or throttle body. In some embodiments of the invention, the conditioning fluid is introduced onto an internal structure or one or more projections positioned within the exhaust device, where the conditioning fluid is vaporised. Preferably, the flow of hot exhaust gas passing through the exhaust device increases conditioning fluid vaporisation. The internal structure or one or more projections may or may not extend across the entire internal diameter of the exhaust device. The internal structure or one or more projections may serve as a substrate for the conditioning fluid and provide a large surface area for the conditioning fluid to spread over, ensuring efficient interaction between the conditioning fluid and the exhaust gas. In some embodiments, the introduction of the conditioning fluid onto an internal structure / or one or more projections may be provided by capillary action or may be gravity fed. In other embodiments a dosing device may be employed to controllably introduce a conditioning fluid. Preferably, the internal structure or one or more projections is a mesh is positioned within the injection chamber. Although in other embodiments the mesh may be positioned within the expansive cone or contracting cone portions so that the condition fluid is introduced into a flow path of the exhaust gas in the injection chamber. The mesh is typically made from a thermally conductive material, such as stainless steel, aluminium, or copper, which allows for rapid heat transfer from the exhaust gas to the conditioning fluid. As the exhaust gas flows through the exhaust device, the temperature difference causes the conditioning fluid to evaporate or vaporise 2026202912   17 Apr 2026 as the exhaust gas comes into contact with the mesh, cooling the exhaust gas and reducing its temperature. The heat exchange process may be enhanced by the design and / or geometry of the internal structure or one or more projections, so as to increase the rate of vaporisation whilst minimally impeding on the backpressure of the exhaust. The present invention is predicated in part on the skilled effort and experimentation of the inventor in identifying previously unrecognised benefit to the power and efficiency of an internal combustion engine that results from the selective injection of a conditioning fluid into an exhaust device according to the present invention. Preferred examples of the invention include injecting the conditioning fluid, in a preferred example water, into an internal combustion engine exhaust under predetermined operating conditions. As the coolant fluid, such as water, is injected into the exhaust flow it turns from a liquid into gas (e.g. steam) and in doing so absorbs heat from the exhaust gases around it. The exhaust gases are cooled which reduces the hydraulic resistance (back-pressure) of the exhaust system and increases peak power. The exhaust device described herein is suitable for use with both two-stroke and four-stroke internal combustion engines. In some embodiments of the invention the exhaust device is configured for use with an internal combustion engine, excluding two-stroke engines. Regardless of the internal engine type, the exhaust device may be adapted in size, shape, and / or internal structure to suit the specific exhaust gas temperature, pressure, and / or pulsation profile of the engine, so as to improve engine performance, efficiency, reliability, and reducing air pollutant emissions. In certain embodiments, the exhaust device is configured for integration with an exhaust gas recirculation (EGR) system. In an EGR system at least a portion of the exhaust gas is diverted from the main exhaust flow path and is reintroduced into the engine's intake system to reduce nitrogen oxide (NOX) emissions. In such embodiments, the exhaust device may be positioned either upstream or downstream of the EGR take-off point. In two-stroke engines, which expel exhaust gases often concurrently with the intake of fresh charge of fuel-oxidiser mixture, the exhaust device may assist in scavenging, reducing unburned hydrocarbon emissions, and preventing loss of a fresh charge of fuel air mixture by maintaining optimal backpressure conditions. In four-stroke engines, the exhaust device may assist in scavenging, function to modulate the exhaust gas temperature and flow, and reduce air pollutant emissions. By injecting a conditioning 2026202912   17 Apr 2026 fluid into the exhaust device as part of an exhaust system of a four-stroke internal combustion engine, this may enhance engine performance, efficiency, and / or reduce air pollutant emissions. When water is used as the conditioning fluid and introduced into the injection chamber and mixed with the exhaust gas of a four-stroke internal combustion engine, it has been found to improve engine performance and / or provide more complete combustion. Without wishing to be bound by theory, it is believed that the water rapidly vaporises due to the high temperature of the exhaust gas, and generates a steam within the injection chamber that when passes through the contractive cone portions drastically increase the mass flow rate and / or exhaust gas pressure. This is believed to improve the extraction of exhaust gas from the engine cylinder. Additionally, the water vapour and atomised water is believed to reduce localized hot spots and thermal gradients within the exhaust system, extending exhaust component life and facilitate exhaust gas flow. When water is used as the conditioning fluid and introduced into the injection chamber and mixed with the exhaust gas of a four-stroke internal combustion engine, it has been found to significantly reduce emissions of carbon monoxide (CO). Without wishing to be bound by theory, it is believed that the water is vaporised (steam) within the injection chamber shifts the equilibrium position of the water-gas shift reaction to convert the residual CO into carbon dioxide (CO2) and hydrogen gas, thereby reducing the concentration of toxic CO emissions. Additionally, when water is used as the conditioning fluid and introduced into the injection chamber and mixed with the exhaust gas of a four-stroke internal combustion engine, it has been found to significantly reduce emissions of unburnt hydrocarbons. Without wishing to be bound by theory, it is believed that the water is vaporised (steam) within the injection chamber of the exhaust device may create backpressure modulation that contributes to improved cylinder clearing, particularly under transient load conditions. Alternatively, it is thought that the presence of steam in the exhaust device may promote further oxidation of hydrocarbons that were not fully combusted in the engine cylinder. Turning to the figure 1 there is shown a schematic view of an internal combustion engine (4) includes at least one cylinder having a cylinder wall (11) defining a combustion chamber (12) in a top portion of the cylinder. The combustion chamber (12) has an inlet port (13) and an outlet (exhaust) port 14. The inlet port (13) is selectively opened and closed by an inlet valve (15) controlled by an inlet valve cam (16). The outlet port (14) is selectively opened and closed by an outlet valve (17) controlled by an outlet valve cam (18). An inlet manifold (19) communicates with the inlet port (13) for the introduction of a fuel and oxidiser (usually air) mixture (20) into the 2026202912   17 Apr 2026 combustion chamber (12) during an open period of the inlet port (13). The fuel air mixture (20) is ignited either by a sparkplug (21), or in some instances pressure. Combustion of the fuel air mixture (20) results in expansion of high-temperature and high-pressure (exhaust) gases that directly apply a force to a piston (22) of the engine. The piston (22) is connected with a crankshaft (23) via a conrod (24) such that linear movement of the piston (22) within the cylinder is translated to a rotational output of the engine (4). After combustion gases have moved piston (22) down the cylinder the exhaust gas (3) is allowed to exit the combustion chamber (12) through the exhaust port (14) into an exhaust manifold (25) connected with the exhaust port (14). The exhaust manifold (25) interconnects with an exhaust device (1) according to the present invention (1). The exhaust gas (3) passes through the expansive cone portion (2), through to the injection chamber portion (5). In the embodiment shown, the injection chamber (5) includes a fluid inlet port (7) where conditioning fluid (8) is introduced into a flow path of the exhaust gas (3) within the injection chamber portion (5), so that the conditioning fluid (8) mixes with the exhaust gas (3). As shown in Figure 1, the expansive cone portion (2) has a convex profile. The exhaust gas (3) conditioned with the conditioning fluid (8) then passes through the contractive cone portion (6) and enters into a pipe (duct) (26) interfaced with the contractive cone portion (6). In the embodiment shown, the exhaust device (1) is part of the internal combustion engine exhaust gas flow system which guides the exhaust gas (3) away from the engine (1) where they are vented to the open air. As shown in the embodiment of the invention shown in Figure 1, the internal combustion engine exhaust gas flow system according to the invention includes a reservoir (9) for housing the conditioning fluid (8). The reservoir (9) includes an accessible inlet port (27) for adding conditioning fluid (8) into the reservoir (9). A pump (28) is fluidically connected with the reservoir (9) and is used to increase the pressure of the conditioning fluid (8). A spray nozzle (29) is fluidically connected with the pump (28) by conduit (30). The spray nozzle (29) is arranged in a wall of the injection chamber (5) to deliver conditioning fluid from the reservoir (9) into the injection chamber (5). A flow control mechanism (31) is connected with the spray injector (29) and pump (28) and is arranged to activate the injector (29) by an actuator (32) to deliver conditioning fluid from the reservoir (9) under desired operating conditions of the engine. In some examples the actuator (31) may be programmed to continuously inject conditioning fluid into the exhaust. However, in practice the size of the reservoir (9) may dictate that conditioning fluid is only introduced into the injection chamber (5) during predefined operating conditions of the engine (4). These operating conditions may be during certain operating demands required of the engine, such as higher operating speeds or where higher power is requested. The selected periods may be during the whole operating cycle of the engine or only during periodic shorter periods of the operating cycle such as during a brief period when an open position of an inlet port (13) overlaps 2026202912   17 Apr 2026 with an open position of an exhaust port (14) to assist with scavenging the combustion chamber (12). As shown in Figure 2, an exhaust manifold (25) is interfaced with a four-stroke, horizontally opposed six-cylinder engine (4), wherein only three cylinders are shown for clarity. The headers of the exhaust manifold (25) are of substantially equal length header. The gas flow path distance from each individual exhaust ports of the engine (4) and the point of convergence in the exhaust manifold (25) are substantially identical, or identical. The exhaust gas produced by the engine (4) flows through the exhaust manifold (25) to the exhaust device (1). As shown in Figure 1 whilst the exhaust gas (3) flows from the convex expansive cone (2) into the injection chamber (5) it is conditioned with the conditioning fluid (8) from the reservoir (9). The reservoir (9) includes an accessible inlet port (27) for adding conditioning fluid (8) into the reservoir (9). A pump (28) is fluidically connected with the reservoir (9) and is used to increase the pressure of the conditioning fluid (8). A spray nozzle (29) is fluidically connected with the pump (28) by conduit (30). The spray nozzle (29) is arranged in a wall of the injection chamber (5) to deliver conditioning fluid from the reservoir (9) into the injection chamber (5) by spraying it. A flow control mechanism (31) is connected with the spray injector (29) and pump (28) and is arranged to activate the injector (29) by an actuator (32) to deliver conditioning fluid from the reservoir (9) under desired operating conditions of the engine. As shown in Figure 2, the pump (28) may be controlled by a switch (33), and as shown the switch is an electronic pressure switch. The controller (34) of the dosing device (10) may independently control the actuator (32) and switch (33) to modulate introduction of conditioning fluid into the injection chamber (5). The dosing device (10) includes a feedback control system (35), where at least one sensor provides real-time data to the controller (34), which modulates the actuator (32) to fine-tune conditioning fluid (8) introduction via the flow control mechanism (31) based on the operating parameters of the engine (4). EXAMPLES The internal combustion engine of the test setup was a Toyota model ‘2E’, 1.3L (1,295 cc) single overhead camshaft (SOHC), 4-cylinder 4-stroke engine mounted in a 1991 Toyota Corolla Hatchback (‘test vehicle’). A custom-made exhaust device according to the present invention was connected to the stock exhaust manifold through a flanged joint, and then interfaced with the standard exhaust system of the test vehicle. Distilled water was used as the conditioning fluid and was pumped from a reservoir using a Shurflo 6.8LPM 107 PSI pump model 8000-547-189. The fluid inlet port was disposed in the injection chamber of the exhaust device, and was fitted with a brass 1 / 8’’ BSP socket threaded with a Brass Hose Tail Fitting 1 / 8'' NPT Male 10mm Hose on the 2026202912   17 Apr 2026 external face of the injection chamber. A 10mm hose was connected between the Shurflo pump and the brass tail fitting to allow the transfer of pressurised water from the reservoir to the injection chamber. The brass 1 / 8’’ BSP socket at the fluid inlet port was also threaded with a brass Spraying Systems Co., VeeJet® spray nozzle, part code H1 / 8VV-11001. During testing, the pump was continually run at a rate of 3.8L / min. Emissions testing was performed on an Opus 40 gas analyser. Results of the testing is shown below in Table 1, where the rotational speed of the Toyota 2E engine was maintained at approximately 2000 revolutions per minute (RPM). Exhaust type (A) Unmodified factory exhaust (control) (B) Exhaust Device (C) Exhaust Device (D) Exhaust Device Addition of Conditioning fluid No No Yes Yes Runtime 10 sec 10 sec 10 sec 48 sec Carbon monoxide 0.52% vol 0.30% vol 0.35% vol 0.32% vol Carbon dioxide 13.6% vol 13.6% vol 14.3% vol 14.3% vol Hydrocarbon 241 ppm 272 ppm 86 ppm 87 ppm Oxygen 2.45 % vol 2.57% vol 1.59% vol 1.61% Lambda 0.094 0.107 0.062 0.062 Table 1: Emissions testing results for carbon monoxide, carbon dioxide hydrocarbons, and oxygen 2026202912   17 Apr 2026 As can be seen in table 1, the exhaust device according to the invention (B) substantially reduced the production of carbon monoxide, whilst the concentration of hydrocarbons increased relative to the factory exhaust (A). By introducing water as a conditioning fluid directly into the injection chamber of the exhaust device (C), this decreased the concentration of unburnt hydrocarbons when compared to when water was not injected (B). Along with the decrease in oxygen and increase in carbon dioxide this indicates that the introduction of water into the exhaust device increases the engine’s combustion efficiency (C). Moreover, the same results were obtained when the exhaust emissions were measured after the engine had been run for 48 seconds (D). This indicates that the improvement in combustion efficiency is a prolonged effect and is not associated with engine start-up. It is believed that the increase in carbon monoxide when water is injected into the exhaust device, compared to when water is not injected into the exhaust device is due to the more complete combustion of the hydrocarbons (fuel), as compared to when water is not introduced. To understand whether the injection of water into the exhaust device increases combustion efficiency in a four-stroke motor, the power and torque produced by the test vehicle were measured. Power and torque measurements for test vehicle were performed on a roller chassis dynamometer manufactured by Mainline Automotive Equipment Pty Ltd, with a ramp rate of 10km / h per second. Figure 3 graphically illustrates power curves for the test vehicle when fitted with: (A) the unmodified factory exhaust, and (B) with the exhaust device according to the invention without the selective injection of water. The exhaust device according to the invention was found the improve engine power at speeds between 65 km / h and 80 km / h. Figure 4 graphically illustrates torque curves for the test vehicle when fitted with: (A) the unmodified factory exhaust, and (B) with the exhaust device according to the invention without the selective injection of water. The exhaust device according to the invention was found the improve engine torque at speeds between 65 km / h and 80 km / h. Figure 5 graphically illustrates power curves for the test vehicle when fitted with: (A) the unmodified factory exhaust, and (C) with the exhaust device according to the invention with the injection of water into the injection chamber. The exhaust device according to the invention was found the improve engine power at speeds between 65 km / h and 120 km / h. Figure 6 graphically illustrates torque curves for the test vehicle when fitted with: (A) the unmodified factory exhaust, and (C) with the exhaust device according to the invention with the 2026202912   17 Apr 2026 selective injection of water. The exhaust device according to the invention was found the improve torque at speeds between 65 km / h and 120 km / h. Unlike conventional exhaust water injection systems, which introduce water upstream of the exhaust manifold or downstream of after-treatment devices, the present invention introduces conditioning fluid into a defined injection chamber disposed at a location downstream of the exhaust manifold and upstream of an exhaust outlet, and in some examples a defined injection chamber disposed between an expansive cone and a contractive cone. The improvements in torque and power with the introduction of water into the injection chamber of the exhaust device according to the invention, are consistent with the emission testing results. That is, the introduction of water into the injection chamber of the exhaust device according to the invention increases combustion efficiency and / or engine efficiency, and by doing so reduces air pollutant emissions. Unless the context clearly requires otherwise, throughout the description and the claims, the words “comprise”, “comprising”, and the like, are to be construed in an inclusive sense as opposed to an exclusive or exhaustive sense, that is to say, in the sense of “including, but not limited to”. The entire disclosures of all applications, patents and publications cited above and below, if any, are herein incorporated by reference. Reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in the field of endeavour in any country in the world. The technology may also be said broadly to consist in the parts, elements and features referred to or indicated in the specification of the application, individually or collectively, in any or all combinations of two or more of said parts, elements or features. Where in the foregoing description reference has been made to integers or components having known equivalents thereof, those integers are herein incorporated as if individually set forth. It should be noted that various changes and modifications to the presently preferred embodiments described herein will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the spirit and scope of the invention and without diminishing its attendant advantages. It is therefore intended that such changes and modifications be included within the present invention.

Claims

1. An exhaust device for an internal combustion engine exhaust gas flow system, said exhaust device comprising:an expansive cone portion adapted to receive exhaust gas produced by combustion within an internal combustion engine;an injection chamber portion fluidly coupled to the expansive cone portion for receiving exhaust gas from the expansive cone portion and configured to allow for turbulent mixing of exhaust gas within the injection chamber portion; anda contractive cone portion fluidly coupled to the injection chamber portion, the contractive cone portion being configured to increase exhaust gas pressure after the exhaust gas exits the injection chamber portion,wherein the expansive cone, injection chamber, or contractive cone portions include at least one fluid inlet port for introducing a conditioning fluid into a flow path of exhaust gas within the injection chamber portion, so that the conditioning fluid mixes with said exhaust gas.

2. The exhaust device according to claim 1, wherein the fluid inlet port is disposed in a sidewall of the expansive cone portion, injection chamber portion and / or the contractive cone portion.

3. The exhaust device according to claim 1 or claim 2, wherein the injection chamber includes at least one fluid inlet port for introducing a conditioning fluid into a flow path of exhaust gas within the injection chamber portion.

4. The exhaust device according to any one of claims 1-3, wherein the fluid inlet port is adapted to receive a spray nozzle for directing the conditioning fluid into the interior of the injection chamber portion.

5. The exhaust device according to any one of claims 1-3, wherein the exhaust device further comprises a spray nozzle received by the fluid inlet port, for directing the conditioning fluid into the interior of the injection chamber portion.

6. The exhaust device according to claim 5, wherein the spray nozzle is a flat spray nozzle.

7. The exhaust device according to any one of claims 1-4, wherein the expansive cone portion has a convex profile.2026202912   17 Apr 20268. The exhaust device according to any one of claims 1-5, wherein a side face of the contractive cone portion has a straight taper.

9. An internal combustion engine exhaust gas flow system, said exhaust gas flow system comprising:an exhaust device according to any one of claims 1-8;a reservoir for housing a conditioning fluid; anda dosing device configured to controllably introduce a conditioning fluid from the reservoir into a flow path of an exhaust gas within the injection chamber portion of the exhaust device.

10. The internal combustion engine exhaust gas flow system according to claim 9, further comprising a pump fluidically connected with the reservoir to increase the pressure of the conditioning fluid.

11. The internal combustion engine exhaust gas flow system according to claim 9 or claim 10, wherein the dosing device includes a flow control mechanism and an actuator for controlling the flow control mechanism.

12. The internal combustion engine exhaust gas flow system according to any one of claims 911, wherein the flow control mechanism is a solenoid valve.

13. The internal combustion engine exhaust gas flow system according to any one of claims 912, wherein the conditioning fluid is water.

14. The internal combustion engine exhaust gas flow system according to any one of claims 913, wherein the dosing device further comprises a sensor to monitor a conditioning fluid flow rate, pressure or volume.

15. A method of improving engine efficiency, the method including:providing a conditioning fluid; andintroducing the conditioning fluid into a flow path of an exhaust gas in an injection chamber of an exhaust device according to any one of claims 1-8.

16. A method of reducing air pollutant emissions, the method including:2026202912   17 Apr 2026providing a conditioning fluid; andintroducing the conditioning fluid into a flow path of an exhaust gas in an injection chamber of an exhaust device according to any one of claims 1-8.

17. The method according to claim 15 or claim 16, wherein the conditioning fluid is water.

18. The method according to any one of claims 15-17, wherein the conditioning fluid is introduced when a rotational speed of the engine is above a predetermined value.

19. The method according to any one of claims 15-18, wherein introducing the conditioning fluid comprises spraying the conditioning fluid into the flow path of the exhaust gas in the injection chamber.

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