An analysis method and device for infrared stealth performance of a ship power exhaust system

Abstract

The application relates to the field of ship infrared stealth technology and discloses a method and device for analyzing the infrared stealth performance of a ship power exhaust system, wherein the method comprises the following steps: according to a preset flow field calculation model, a chimney opening window geometric model of the ship power exhaust system is built; according to the chimney opening window geometric model, fluid simulation is carried out on the chimney part of the ship power exhaust system, and the corresponding relationship between the chimney opening window area and the average temperature of the chimney outlet is obtained; according to the average temperature of the chimney outlet corresponding to different chimney opening window areas, the infrared radiation brightness corresponding to different chimney opening window areas is calculated, and the corresponding relationship between the chimney opening window area and the infrared radiation brightness is obtained; and according to the corresponding relationship among the chimney opening window area, the average temperature of the chimney outlet and the infrared radiation brightness, the chimney opening window area corresponding to the maximum infrared stealth performance of the ship power exhaust system is determined.

Description

Technical Field

[0001] This application relates to the field of ship infrared stealth technology, for example to a method and apparatus for analyzing the infrared stealth performance of a ship's power exhaust system. Background Technology

[0002] Infrared stealth technology for ships aims to suppress infrared radiation, thereby achieving stealth. This is achieved by lowering the temperature of the hull, especially its hot spots, to near the ambient temperature, making it difficult for infrared detection systems to detect the target. Currently, the main methods used in infrared stealth technology include installing infrared suppressors, applying infrared stealth materials, and adding water mist cooling systems. Infrared terminal guidance is a significant threat to ships in modern warfare. Infrared radiation characteristics are a primary detection target for precision-guided systems, possessing strong jamming capabilities and being difficult to intercept. Therefore, a ship's infrared stealth performance is one of the important indicators for evaluating its battlefield survivability.

[0003] Therefore, the smokestack of a ship's power exhaust system, as a major infrared radiation highlight, is a key research target for infrared stealth technology. By drawing in cooling air through exhaust louvers, the high-temperature exhaust from the power system mixes with the drawn-in cooling air, reducing the exhaust temperature and infrared radiation at the smokestack.

[0004] In the process of implementing the embodiments of this disclosure, at least the following problems were found in the related art:

[0005] There is limited research on the impact of the louver opening area in the chimney trap area on infrared radiation, which is insufficient to support the infrared stealth design requirements of ship louvers. Summary of the Invention

[0006] To provide a basic understanding of some aspects of the disclosed embodiments, a brief summary is given below. This summary is not intended as a general commentary, nor is it intended to identify key / important components or describe the scope of protection of these embodiments, but rather as a prelude to the detailed description that follows.

[0007] This disclosure provides a method, apparatus, computing device, and storage medium for analyzing the infrared stealth performance of a ship's power exhaust system. It establishes a louver flow field model, calculates the exhaust temperature of the power exhaust system under different louver opening areas at the chimney location, analyzes the influence of the louver opening area on the average temperature of the exhaust system, and obtains the law governing the influence of the louver opening area on the infrared radiation characteristics of the chimney location.

[0008] In some embodiments, the method for analyzing the infrared stealth performance of the ship's power exhaust system includes:

[0009] Based on the pre-set flow field calculation model, a geometric model of the chimney opening of the ship's power exhaust system is constructed.

[0010] Based on the aforementioned chimney window geometric model, fluid simulation was performed on the chimney section of the ship's power exhaust system to obtain the correspondence between the chimney window area and the average temperature at the chimney outlet.

[0011] Based on the average temperature at the chimney outlet corresponding to different chimney opening areas, the infrared radiation brightness corresponding to different chimney opening areas is calculated, and the correspondence between chimney opening area and infrared radiation brightness is obtained.

[0012] Based on the correlation between chimney window area, average chimney outlet temperature, and infrared radiation brightness, the chimney window area that maximizes the infrared stealth performance benefit of the ship's power exhaust system is determined.

[0013] Optionally, the geometric model for constructing the chimney window of the ship's power exhaust system includes:

[0014] The chimney geometry of the ship's power exhaust system is constructed and a window area is set. The chimney geometry is then divided into grids.

[0015] Set the target speed of the ship and the free-slip boundary conditions in the simulated wind tunnel;

[0016] The correctness of the chimney window geometry model, mesh generation, loading, and boundary conditions is determined by analyzing the convergence.

[0017] Optionally, the fluid simulation of the chimney portion of the ship's power exhaust system includes:

[0018] The temperature distribution on the central interface of the chimney geometry is obtained under different chimney opening areas;

[0019] The temperature distribution of the surrounding wall surface of the chimney geometry is obtained under different chimney opening areas;

[0020] The temperature distribution at the rear of the chimney geometry was obtained under different chimney opening areas.

[0021] The temperature distribution of the flue gas flow field at the rear of the chimney geometry is obtained under different chimney opening areas.

[0022] Optionally, the step of calculating the infrared radiation brightness corresponding to different chimney opening areas based on the average temperature at the chimney outlet corresponding to different chimney opening areas includes:

[0023] The exhaust pipe of the chimney is considered as a blackbody radiation source. The infrared radiation intensity at the outlet of the exhaust pipe is calculated using the temperature field at the outlet. The infrared radiation intensity L is calculated using the following formula:

[0024]

[0025] Where ε = 0.9, and the first radiation constant c1 = 3.7418 × 10⁻⁶. 4 W·μm 4 / cm 2 The second radiation constant c1 = 1.438 × 10 4 μm·K.

[0026] Optionally, determining the chimney window area that maximizes the infrared stealth performance benefit of the ship's power exhaust system based on the correspondence between the chimney window area, the average temperature at the chimney outlet, and the infrared radiation brightness includes:

[0027] Multiple sets of experimental data were obtained for the average temperature and infrared radiation brightness of the chimney outlet under different chimney opening areas.

[0028] By fitting the multiple sets of experimental data using data analysis software, the corresponding relationship between the chimney window area and the average temperature at the chimney outlet, as well as the corresponding relationship between the chimney window area and the infrared radiation brightness, were obtained.

[0029] Based on the correlation between the chimney window area and the average temperature at the chimney outlet, as well as the correlation between the chimney window area and the infrared radiation brightness, and by comprehensively evaluating the benefits of ship structural strength and chimney window area to infrared stealth performance, the chimney window area corresponding to maximizing infrared stealth benefits is determined.

[0030] Optionally, the flow field calculation model includes the mass conservation equation, the momentum conservation equation, the turbulence model based on turbulent kinetic energy-turbulent kinetic energy dissipation rate, the energy conservation equation, and the material composition conservation equation.

[0031] In some embodiments, the device for analyzing the infrared stealth performance of the marine power exhaust system is characterized by comprising:

[0032] The model building module is configured to build a geometric model of the chimney opening of the ship's power exhaust system based on a preset flow field calculation model.

[0033] The fluid simulation module is configured to perform fluid simulation on the chimney section of the ship's power exhaust system based on the chimney window geometry model, and obtain the correspondence between the chimney window area and the average temperature at the chimney outlet.

[0034] The infrared radiation brightness module is configured to calculate the infrared radiation brightness corresponding to different chimney opening areas based on the average temperature of the chimney outlet corresponding to different chimney opening areas, and obtain the correspondence between chimney opening area and infrared radiation brightness.

[0035] The window area selection module is configured to determine the corresponding chimney window area that maximizes the infrared stealth performance benefit of the ship's power exhaust system based on the correspondence between the chimney window area, the average temperature at the chimney outlet, and the infrared radiation brightness.

[0036] In some embodiments, the computing device includes a processor and a memory storing program instructions, the processor being configured to, when running the program instructions, execute the method for analyzing the infrared stealth performance of a marine power exhaust system as described in this application.

[0037] In some embodiments, the storage medium stores program instructions that, when executed, perform the method for analyzing the infrared stealth performance of a marine power exhaust system as described in this application.

[0038] The method, apparatus, computing device, and storage medium for analyzing the infrared stealth performance of marine power exhaust systems provided in this disclosure can achieve the following technical effects:

[0039] This application studies the chimney section with added louvers, conducts fluid simulation of the chimney section of the ship's power exhaust system, obtains the correspondence between the chimney window area and the average temperature at the chimney outlet, and establishes a chimney window geometric model by simplifying the actual structure to simulate the influence of the chimney window area on the average temperature at the chimney outlet from the perspectives of exhaust temperature, infrared radiation brightness, flow field structure and characteristics of the ship's power system under different chimney window areas. It also obtains the variation law of the influence of the chimney window area on the infrared radiation characteristics of the chimney section, and ultimately maximizes the infrared stealth performance benefits of the ship's power exhaust system.

[0040] The above general description and the description below are exemplary and illustrative only and are not intended to limit this application. Attached Figure Description

[0041] One or more embodiments are illustrated by way of example with reference to the accompanying drawings. These illustrations and drawings do not constitute a limitation on the embodiments. Elements having the same reference numerals in the drawings are shown as similar elements. The drawings are not to be scaled. And wherein:

[0042] Figure 1 This is a schematic diagram of an analysis method for the infrared stealth performance of a marine power exhaust system provided in this application;

[0043] Figure 2 This is a schematic diagram of another method for analyzing the infrared stealth performance of a marine power exhaust system provided in this application;

[0044] Figure 3 This is a schematic diagram of the geometry of a chimney provided in this application;

[0045] Figure 4 This is a global schematic diagram of the chimney geometry after mesh generation, provided in this application;

[0046] Figure 5 This is a partial schematic diagram of the chimney's geometric structure after mesh generation, provided in this application;

[0047] Figure 6 This is a schematic diagram of the convergence curve of an infrared suppressor diffusion calculation provided in this application;

[0048] Figure 7 This is a schematic diagram of the convergence curve of an unsteady calculation using a separate eddy algorithm provided in this application;

[0049] Figure 8 This is a schematic diagram of another method for analyzing the infrared stealth performance of a marine power exhaust system provided in this application;

[0050] Figure 9 This is a schematic diagram of the temperature distribution on the central interface of a chimney geometry provided in this application;

[0051] Figure 10 This is a schematic diagram of the temperature distribution on the surrounding wall of a chimney geometry provided in this application;

[0052] Figure 11 This is a schematic diagram of the temperature distribution at the rear of a chimney geometry provided in this application;

[0053] Figure 12 This is a schematic diagram of the temperature distribution of the flue gas flow field at the rear of a chimney geometry provided in this application;

[0054] Figure 13 This is a schematic diagram of another method for analyzing the infrared stealth performance of a marine power exhaust system provided in this application;

[0055] Figure 14 This is a schematic diagram illustrating the relationship between the chimney opening area and the average temperature at the chimney outlet, as provided in this application.

[0056] Figure 15 This is a schematic diagram illustrating the correspondence between the chimney window area and infrared radiation brightness provided in this application;

[0057] Figure 16 This is a schematic diagram of a computing device provided in this application;

[0058] Figure 17 This is a schematic diagram of an infrared stealth performance analysis device for a marine power exhaust system provided in this application. Detailed Implementation

[0059] To provide a more detailed understanding of the features and technical content of the embodiments of this disclosure, the implementation of the embodiments of this disclosure will be described in detail below with reference to the accompanying drawings. The accompanying drawings are for illustrative purposes only and are not intended to limit the embodiments of this disclosure. In the following technical description, for ease of explanation, several details are used to provide a full understanding of the disclosed embodiments. However, one or more embodiments may still be implemented without these details. In other cases, well-known structures and devices may be simplified in their depiction to simplify the drawings.

[0060] The terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this disclosure are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of this disclosure described herein. Furthermore, the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion.

[0061] Unless otherwise stated, the term "multiple" means two or more.

[0062] In this embodiment of the disclosure, the character " / " indicates that the objects before and after it are in an "or" relationship. For example, A / B means: A or B.

[0063] The term "and / or" describes an association between objects, indicating that three relationships can exist. For example, A and / or B means: A or B, or A and B.

[0064] The term "correspondence" can refer to an association or binding relationship. The correspondence between A and B means that there is an association or binding relationship between A and B.

[0065] Combination Figure 1 As shown in the embodiments of this disclosure, a method for analyzing the infrared stealth performance of a marine power exhaust system is provided, including:

[0066] Step 101: Based on the preset flow field calculation model, build the chimney window geometric model of the ship's power exhaust system.

[0067] In the embodiments of this application, the chimney window geometric model of the ship's power exhaust system is a part of the flow field calculation model. The chimney window geometric model is autonomously constructed based on the flow field calculation model. Specifically, the flow field calculation model includes the mass conservation equation, the momentum conservation equation, the turbulence model based on turbulent kinetic energy-turbulent kinetic energy dissipation rate, the energy conservation equation, and the material composition conservation equation.

[0068] Optionally, the formula for the mass conservation equation is:

[0069]

[0070] Where ρ is density; t is time; S is the velocity vector; m This is a mass source term, which is generally zero. However, when there is a water droplet evaporation process, the water droplets evaporate into water vapor, causing the mass source term to increase.

[0071] Alternatively, the formula for the momentum conservation equation is:

[0072]

[0073] Where p is the static pressure; For stress tensor; It is the vector of gravitational acceleration; The volume force acting on the external environment (e.g., the volume force generated by the interaction with discrete terms).

[0074] Optionally, the turbulence model based on turbulent kinetic energy-turbulent kinetic energy dissipation rate includes:

[0075]

[0076]

[0077] Where k is the turbulent kinetic energy; ε is the turbulent kinetic energy dissipation rate; G k G is the turbulent kinetic energy generated by the average velocity gradient. b C is the turbulent kinetic energy generated by buoyancy. 1ε C 2ε C 3ε Pr is a constant; Prk is the Prandtl number of turbulent kinetic energy; Prε is the Prandtl number of turbulent kinetic energy dissipation rate; Sr is a constant. k S ε For source terms.

[0078] The formula for turbulent viscosity is:

[0079]

[0080] Among them, C μ It is a constant.

[0081] The constants in the turbulence model are as follows:

[0082] C 1ε =1.44, C 2ε =1.92, C 3ε =0.09, Prk=1.0, Prε=1.3.

[0083] Optionally, the energy conservation equation is formulated as follows:

[0084]

[0085] Where, k eff It is the equivalent thermal conductivity; S represents the diffusion flux of component i; the three terms in parentheses on the right represent energy transfer caused by thermal conduction, diffusion of component i, and viscous dissipation, respectively; H For source terms;

[0086] The formula for the apparent enthalpy of an ideal gas is:

[0087]

[0088] The formula for the enthalpy of incompressible flow is:

[0089]

[0090] Among them, Y i Let i be the mass fraction of substance component i.

[0091] Alternatively, the constraint formulas for enthalpy and energy are as follows:

[0092]

[0093] Where E is internal energy and v is speed.

[0094] Optionally, the formula for the conservation equation of the material composition is:

[0095]

[0096] Among them, S i The source term is the amount of water vapor produced after the water droplets evaporate.

[0097] Step 102: Based on the chimney window geometric model, perform fluid simulation on the chimney section of the ship's power exhaust system to obtain the correspondence between the chimney window area and the average temperature at the chimney outlet.

[0098] In the embodiments of this application, the chimney window geometric model is imported into the fluid calculation software FLUENT. The fluid calculation software FLUENT is used to realize the fluid simulation of the chimney part of the ship's power exhaust system, and to simulate the exhaust temperature, flow field structure and characteristics of the ship's power system under different window area conditions.

[0099] Step 103: Based on the average temperature at the chimney outlet corresponding to different chimney opening areas, calculate the infrared radiation brightness corresponding to different chimney opening areas, and obtain the correspondence between chimney opening area and infrared radiation brightness.

[0100] In the embodiments of this application, based on simulation results, the average temperature at the chimney outlet under different chimney opening areas can be obtained. Furthermore, according to relevant technical viewpoints, this application considers the exhaust pipe at the chimney section as a blackbody radiation source, and calculates the infrared radiation brightness at the outlet of the exhaust pipe using the temperature field at the outlet of the exhaust pipe. The infrared radiation brightness L is calculated using the following formula:

[0101]

[0102] Where ε = 0.9, and the first radiation constant c1 = 3.7418 × 10⁻⁶. 4 W·μm 4 / cm 2 The second radiation constant c1 = 1.438 × 10 4 μm·K.

[0103] Step 104: Based on the correspondence between the chimney window area, the average temperature at the chimney outlet, and the infrared radiation brightness, determine the chimney window area that maximizes the infrared stealth performance benefit of the ship's power exhaust system.

[0104] In the embodiments of this application, by analyzing the influence of the chimney window area on the average temperature of the chimney outlet, this application obtains the variation law of the influence of the chimney window area on the infrared radiation characteristics of the chimney, thereby determining the chimney window area that maximizes the infrared stealth performance benefit of the ship's power exhaust system.

[0105] The method for analyzing the infrared stealth performance of a ship's power exhaust system provided in this disclosure studies the chimney section with louvers, performs fluid simulation on the chimney section of the ship's power exhaust system, obtains the correspondence between the chimney window area and the average temperature at the chimney outlet, establishes a chimney window geometric model by simplifying the actual structure, and simulates the exhaust temperature, infrared radiation brightness, flow field structure and characteristics of the ship's power system under different chimney window areas. This analyzes the influence of the chimney window area on the average temperature at the chimney outlet, obtains the variation law of the influence of the chimney window area on the infrared radiation characteristics of the chimney section, and ultimately maximizes the infrared stealth performance benefits of the ship's power exhaust system.

[0106] In the embodiments of this application, combined with Figure 2 As shown, the geometric model of the chimney opening for the ship's power exhaust system includes:

[0107] Step 201: Construct the chimney geometry of the ship's power exhaust system and set the window area, and divide the chimney geometry into a grid.

[0108] In the embodiments of this application, combined with Figure 3 As shown, this application constructs the chimney geometry of the ship's power exhaust system and provides a window area, the window area being... Figure 3 The rectangular region in the application has an area S that can be initially set to 1 / 4 of the sidewall area of ​​the chimney geometry. This application optimizes the structure by using the size of the window area as a variable to maximize the flow rate directed to the chimney outlet.

[0109] In the embodiments of this application, combined with Figure 4 and 5 As shown, this application uses ICEM to mesh the chimney geometry. The total number of meshes can be 13-15 million elements, all of which are tetrahedral meshes.

[0110] Step 202: Set the target speed of the ship and the free slip boundary conditions of the simulated wind tunnel.

[0111] In the embodiments of this application, the ship is set to sail at a target speed of 10 m / s. Except for the inlet, outlet and internal wall of the chimney geometry, the outer boundary of the calculation area is a free-slip boundary condition simulating a wind tunnel, so as to analyze the influence of different chimney window areas on the average temperature of the chimney outlet.

[0112] Step 203: By analyzing the convergence, the correctness of the chimney window geometry model, mesh generation, loading, and boundary conditions is determined.

[0113] In the embodiments of this application, Figure 6 The convergence curve obtained by infrared suppressor diffusion calculation is shown. Meanwhile, Figure 7 The convergence curve of the Detached-Eddy Simulation (DES) algorithm is shown. Since the DES model is an unsteady simulation, the convergence curve is oscillating, thus verifying the convergence of the chimney window geometry model, mesh generation, loading, and boundary conditions.

[0114] In the embodiments of this application, combined with Figure 8 As shown, the fluid simulation of the chimney section of the ship's power exhaust system includes:

[0115] Step 801: Obtain the temperature distribution on the central interface of the chimney geometry under different chimney opening areas.

[0116] In the embodiments of this application, Figure 9 The diagram illustrates the temperature distribution at the central interface of the chimney geometry, as well as the airflow and heat dissipation process within the chimney. It can be seen that the central airflow temperature is relatively high. Figure 9The window area of ​​the chimney on the upper left is 1.25 m². 2 , Figure 9 The window area of ​​the chimney on the upper right is S m. 2 , Figure 9 The window area of ​​the bottom left chimney is 2S m. 2 , Figure 9 The chimney on the lower right has a window area of ​​1.5S m². 2 .

[0117] Step 802: Obtain the temperature distribution of the surrounding wall surface of the chimney geometry under different chimney opening areas.

[0118] In the embodiments of this application, Figure 10 The temperature distribution of the surrounding wall surface of the chimney geometry is shown, wherein, Figure 10 The window area of ​​the chimney on the upper left is 1.25 m². 2 , Figure 10 The window area of ​​the chimney on the upper right is S m. 2 , Figure 10 The window area of ​​the bottom left chimney is 2S m. 2 , Figure 10 The chimney on the lower right has a window area of ​​1.5S m². 2 .

[0119] Step 803: Obtain the temperature distribution at the rear of the chimney geometry under different chimney opening areas.

[0120] In the embodiments of this application, Figure 11 The temperature distribution at the rear of the chimney geometry is shown, with a height plane of 1.60m, where, Figure 11 The window area of ​​the chimney on the upper left is 1.25 m². 2 , Figure 11 The window area of ​​the chimney on the upper right is S m. 2 , Figure 11 The window area of ​​the bottom left chimney is 2S m. 2 , Figure 11 The chimney on the lower right has a window area of ​​1.5S m². 2 .

[0121] Step 804: Obtain the temperature distribution of the flue gas flow field at the rear of the chimney geometry under different chimney opening areas.

[0122] In the embodiments of this application, Figure 12 The temperature distribution of the flue gas field at the rear of the chimney geometry is shown, exhibiting a significant temperature wake of the flue gas flow lines. Figure 12 The window area of ​​the chimney on the upper left is 1.25 m². 2 , Figure 12 The window area of ​​the chimney on the upper right is S m.2 , Figure 12 The window area of ​​the bottom left chimney is 2S m. 2 , Figure 12 The chimney on the lower right has a window area of ​​1.5S m². 2 .

[0123] In this way, the temperature distribution of the chimney section of a ship's power exhaust system can be accurately simulated under different chimney opening areas.

[0124] In the embodiments of this application, combined with Figure 13 As shown, determining the chimney window area that maximizes the infrared stealth performance benefit of the ship's power exhaust system based on the correspondence between the chimney window area, the average temperature at the chimney outlet, and the infrared radiation brightness includes:

[0125] Step 1301: Obtain multiple sets of experimental data corresponding to the average temperature and infrared radiation brightness of the chimney outlet under different chimney opening areas.

[0126] Step 1302: Fit the multiple sets of experimental data using data analysis software to obtain the correspondence between the chimney window area and the average temperature at the chimney outlet, as well as the correspondence between the chimney window area and the infrared radiation brightness.

[0127] Step 1303: Based on the correspondence between the chimney window area and the average temperature at the chimney outlet, and the correspondence between the chimney window area and the infrared radiation brightness, and by comprehensively evaluating the benefits of ship structural strength and chimney window area to infrared stealth performance, determine the chimney window area corresponding to maximizing infrared stealth benefits.

[0128] In practical engineering applications, taking a diesel engine chimney as an example, the emissivity at the exhaust pipe outlet of the diesel engine chimney is set to 0.9, that is, it is regarded as a gray body, and its temperature distribution follows the temperature field at the pipe outlet. The infrared radiation brightness at the chimney outlet is obtained by calculation.

[0129] This application uses the chimney window area Sm 2 Using the condition as a baseline, with temperature T and infrared radiation intensity L, Table 1 shows the average chimney outlet temperature and infrared radiation intensity for different chimney opening areas:

[0130] Table 1

[0131]

[0132] As can be seen from Table 1, the window opening is 2Sm 2 Infrared stealth is most effective at this time.

[0133] In addition, using the experimental data on temperature and infrared radiance for the four sets of chimney opening areas in Table 1, the four sets of experimental data were fitted using MATLAB software to obtain the relationship between chimney opening area and average chimney outlet temperature, as well as the relationship between chimney opening area and infrared radiance, as shown below. Figure 14 and Figure 15 As shown.

[0134] from Figure 14 and Figure 15 As can be seen, the chimney louver area directly affects the average temperature at the chimney outlet, thus influencing the infrared radiation brightness of the chimney. In the infrared stealth design of the chimney, from an infrared stealth perspective, the lower the exhaust outlet temperature, the better. However, when the louver area reaches a certain value, the radiation-inducing effect of the louvers weakens, and the rate of temperature change decreases. Furthermore, considering the actual dimensions of the chimney, the louver area cannot be increased indefinitely. Taking all factors into account, considering the structural strength of the chimney outer panel, a louver louver area of ​​2.5Sm is recommended. 2 At that time, the infrared stealth effect is better.

[0135] Thus, by calculating the impact on the exhaust temperature and infrared radiation brightness of the ship's power system under four different chimney opening areas, it was found that the exhaust temperature and infrared radiation brightness decrease as the opening area increases, but the slope of the change in infrared radiation brightness decreases continuously as the opening area increases. Taking into account the infrared stealth benefits brought by structural strength and opening area, the optimal louver opening area is 60% to 65% of the side wall area.

[0136] Combination Figure 16 As shown in the figure, this disclosure provides an analysis device for the infrared stealth performance of a marine power exhaust system, comprising:

[0137] Model building module 1601 is configured to build a geometric model of the chimney opening of the ship's power exhaust system based on a preset flow field calculation model.

[0138] The fluid simulation module 1602 is configured to perform fluid simulation on the chimney part of the ship's power exhaust system based on the chimney window geometric model, and obtain the correspondence between the chimney window area and the average temperature at the chimney outlet.

[0139] The infrared radiation brightness module 1603 is configured to calculate the infrared radiation brightness corresponding to different chimney opening areas based on the average temperature of the chimney outlet corresponding to different chimney opening areas, and obtain the correspondence between chimney opening area and infrared radiation brightness.

[0140] The window area selection module 1604 is configured to determine the corresponding window area of ​​the chimney that maximizes the infrared stealth performance benefit of the ship's power exhaust system based on the correspondence between the chimney window area, the average temperature of the chimney outlet, and the infrared radiation brightness.

[0141] Optionally, the model building module 1601 is specifically configured as follows:

[0142] The chimney geometry of the ship's power exhaust system is constructed and a window area is set. The chimney geometry is then divided into grids.

[0143] Set the target speed of the ship and the free-slip boundary conditions in the simulated wind tunnel;

[0144] The correctness of the chimney window geometry model, mesh generation, loading, and boundary conditions is determined by analyzing the convergence.

[0145] Optionally, the fluid simulation module 1602 is specifically configured as follows:

[0146] The temperature distribution on the central interface of the chimney geometry is obtained under different chimney opening areas;

[0147] The temperature distribution of the surrounding wall surface of the chimney geometry is obtained under different chimney opening areas;

[0148] The temperature distribution at the rear of the chimney geometry was obtained under different chimney opening areas.

[0149] The temperature distribution of the flue gas flow field at the rear of the chimney geometry is obtained under different chimney opening areas.

[0150] Optionally, the infrared radiation brightness module 1603 is specifically configured as follows:

[0151] The exhaust pipe of the chimney is considered as a blackbody radiation source. The infrared radiation intensity at the outlet of the exhaust pipe is calculated using the temperature field at the outlet. The infrared radiation intensity L is calculated using the following formula:

[0152]

[0153] Wherein, ε = 0.9, and the first radiation constant c1 = 3.7418 × 10⁻⁶. 4 W·μm 4 / cm 2 The second radiation constant c1 = 1.438 × 10 4 μm·K.

[0154] Optionally, the window area selection module 1604 is specifically configured as follows:

[0155] Multiple sets of experimental data were obtained for the average temperature and infrared radiation brightness of the chimney outlet under different chimney opening areas.

[0156] By fitting the multiple sets of experimental data using data analysis software, the corresponding relationship between the chimney window area and the average temperature at the chimney outlet, as well as the corresponding relationship between the chimney window area and the infrared radiation brightness, were obtained.

[0157] Based on the correlation between chimney window area and average chimney outlet temperature, and the correlation between chimney window area and infrared radiation brightness, and by comprehensively evaluating the benefits of ship structural strength and chimney window area on infrared stealth performance, the chimney window area corresponding to maximizing infrared stealth benefits is determined.

[0158] The infrared stealth performance analysis device for marine power exhaust systems provided in this disclosure is used to study the chimney section with louvers installed. Fluid simulation of the chimney section of the marine power exhaust system is performed to obtain the correspondence between the chimney window area and the average temperature at the chimney outlet. By simplifying the actual structure, a geometric model of the chimney window is established to simulate the influence of the chimney window area on the average temperature at the chimney outlet from the perspectives of exhaust temperature, infrared radiation brightness, and flow field structure and characteristics under different chimney window areas. This reveals the variation law of the influence of the chimney window area on the infrared radiation characteristics of the chimney section, ultimately maximizing the infrared stealth performance benefits of the marine power exhaust system.

[0159] Combination Figure 17 As shown, this embodiment of the disclosure provides a computing device, including a processor 170 and a memory 171. Optionally, the device may further include a communication interface 172 and a bus 173. The processor 170, communication interface 172, and memory 171 can communicate with each other via the bus 173. The communication interface 172 can be used for information transmission. The processor 170 can call logical instructions in the memory 171 to execute the infrared stealth performance analysis method of the marine power exhaust system described in the above embodiment.

[0160] Furthermore, the logic instructions in the aforementioned memory 171 can be implemented as software functional units and, when sold or used as independent products, can be stored in a computer-readable storage medium.

[0161] The memory 171, as a computer-readable storage medium, can be used to store software programs and computer-executable programs, such as program instructions / modules corresponding to the methods in the embodiments of this disclosure. The processor 170 executes functional applications and data processing by running the program instructions / modules stored in the memory 171, thereby realizing the method for analyzing the infrared stealth performance of the marine power exhaust system in the above embodiments.

[0162] The memory 171 may include a program storage area and a data storage area. The program storage area may store the operating system and application programs required for at least one function; the data storage area may store data created based on the use of the terminal device. Furthermore, the memory 171 may include high-speed random access memory and may also include non-volatile memory.

[0163] This disclosure provides a storage medium storing computer-executable instructions configured to perform the above-described method for analyzing the infrared stealth performance of a marine power exhaust system.

[0164] The aforementioned storage medium can be a transient computer-readable storage medium or a non-transitory computer-readable storage medium.

[0165] The technical solutions of this disclosure can be embodied in the form of a software product. This computer software product is stored in a storage medium and includes one or more instructions to cause a computer device (which may be a personal computer, server, or network device, etc.) to execute all or part of the steps of the method described in this disclosure. The aforementioned storage medium can be a non-transitory storage medium, including: a USB flash drive, a portable hard drive, a read-only memory (ROM), a random access memory (RAM), a magnetic disk, or an optical disk, and other media capable of storing program code; it can also be a transient storage medium.

[0166] The foregoing description and accompanying drawings fully illustrate embodiments of this disclosure to enable those skilled in the art to practice them. Other embodiments may include structural, logical, electrical, procedural, and other changes. The embodiments represent only possible variations. Individual components and functions are optional unless explicitly required, and the order of operation may vary. Parts and features of some embodiments may be included in or replace parts and features of other embodiments. Moreover, the terminology used in this application is for describing embodiments only and is not intended to limit the claims. As used in the description of embodiments and claims, the singular forms “a,” “an,” and “the” are intended to equally include the plural forms unless the context clearly indicates otherwise. Similarly, the term “and / or” as used in this application means including one or more of the associated listed items and all possible combinations thereof. Additionally, when used in this application, the term "comprise" and its variations "comprises" and / or "comprising" refer to the presence of stated features, integrals, steps, operations, elements, and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components, and / or groups thereof. Without further limitations, an element defined by the phrase "comprises a..." does not exclude the presence of other identical elements in the process, method, or apparatus that includes said element. In this document, each embodiment may focus on the differences from other embodiments, and similar or identical parts between embodiments can be referred to mutually. For methods, products, etc., disclosed in the embodiments, if they correspond to the method section disclosed in the embodiments, the relevant parts can be referred to the description of the method section.

[0167] Those skilled in the art will recognize that the units and algorithm steps of the various examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are implemented in hardware or software depends on the specific application and design constraints of the technical solution. Those skilled in the art can use different methods to implement the described functions for each specific application, but such implementation should not be considered beyond the scope of the embodiments of this disclosure. Those skilled in the art will clearly understand that, for the sake of convenience and brevity, the specific working processes of the systems, devices, and units described above can be referred to the corresponding processes in the foregoing method embodiments, and will not be repeated here.

[0168] The methods and products (including but not limited to devices and equipment) disclosed in the embodiments herein can be implemented in other ways. For example, the device embodiments described above are merely illustrative. For instance, the division of units may be merely a logical functional division, and in actual implementation, there may be other division methods. For example, multiple units or components may be combined or integrated into another system, or some features may be ignored or not executed. In addition, the coupling or direct coupling or communication connection between the shown or discussed units may be through some interfaces, and the indirect coupling or communication connection between devices or units may be electrical, mechanical, or other forms. The units described as separate components may or may not be physically separate. The components shown as units may or may not be physical units, that is, they may be located in one place or distributed across multiple network units. Some or all of the units may be selected to implement this embodiment according to actual needs. Furthermore, the functional units in the embodiments of this disclosure may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit.

[0169] The flowcharts and block diagrams in the accompanying drawings illustrate the architecture, functionality, and operation of possible implementations of systems, methods, and computer program products according to embodiments of this disclosure. In this regard, each block in a flowchart or block diagram may represent a module, segment, or portion of code containing one or more executable instructions for implementing a specified logical function. In some alternative implementations, the functions marked in the blocks may occur in a different order than that shown in the drawings. For example, two consecutive blocks may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. In the descriptions corresponding to the flowcharts and block diagrams in the accompanying drawings, the operations or steps corresponding to different blocks may also occur in a different order than disclosed in the description, and sometimes there is no specific order between different operations or steps. For example, two consecutive operations or steps may actually be executed substantially in parallel, and they may sometimes be executed in reverse order, depending on the functions involved. Each block in a block diagram and / or flowchart, and combinations of blocks in a block diagram and / or flowchart, can be implemented using a dedicated hardware-based system that performs the specified function or action, or using a combination of dedicated hardware and computer instructions.

Claims

1. A method for analyzing the infrared stealth performance of a marine power exhaust system, characterized in that, include: Based on the pre-set flow field calculation model, a geometric model of the chimney opening of the ship's power exhaust system is constructed. Based on the aforementioned chimney window geometry model, fluid simulation is performed on the chimney portion of the ship's power exhaust system to obtain the correspondence between the chimney window area and the average temperature at the chimney outlet. The fluid simulation of the chimney portion of the ship's power exhaust system includes: obtaining the temperature distribution at the central interface of the chimney geometry under different chimney window areas; obtaining the temperature distribution on the surrounding walls of the chimney geometry under different chimney window areas; obtaining the temperature distribution at the rear of the chimney geometry under different chimney window areas; and obtaining the temperature distribution of the flue gas flow field at the rear of the chimney geometry under different chimney window areas. Based on the average chimney outlet temperature corresponding to different chimney opening areas, the infrared radiation brightness corresponding to different chimney opening areas is calculated, thus obtaining the correspondence between chimney opening area and infrared radiation brightness. Specifically, calculating the infrared radiation brightness corresponding to different chimney opening areas based on the average chimney outlet temperature includes: treating the exhaust pipe at the chimney as a blackbody radiation source, and calculating the infrared radiation brightness at the outlet of the exhaust pipe using the temperature field at the outlet of the exhaust pipe. The infrared radiation brightness L is calculated using the following formula: Where ε = 0.9, and the first radiation constant c1 = 3.7418 × 10⁻⁶. 4 W·μm 4 / cm 2 The second radiation constant c2 = 1.438 × 10 4 μm·K; Based on the correlation between chimney window area, average chimney outlet temperature, and infrared radiation brightness, the chimney window area that maximizes the infrared stealth performance benefit of the ship's power exhaust system is determined. This determination involves: acquiring multiple sets of experimental data corresponding to the average chimney outlet temperature and infrared radiation brightness under different chimney window areas; fitting the multiple sets of experimental data using data analysis software to obtain the correlation between chimney window area and average chimney outlet temperature, and the correlation between chimney window area and infrared radiation brightness; and, based on these correlations, comprehensively evaluating the benefits of ship structural strength and chimney window area on infrared stealth performance, determining the chimney window area that maximizes infrared stealth benefits.

2. The analytical method according to claim 1, characterized in that, The geometric model for constructing the chimney window of the ship's power exhaust system includes: The chimney geometry of the ship's power exhaust system is constructed and a window area is set. The chimney geometry is then divided into grids. Set the target speed of the ship and the free-slip boundary conditions in the simulated wind tunnel; The correctness of the chimney window geometry model, mesh generation, loading, and boundary conditions is determined by analyzing the convergence.

3. The analytical method according to claim 1 or 2, characterized in that, The flow field calculation model includes the mass conservation equation, the momentum conservation equation, the turbulence model based on turbulent kinetic energy-turbulent kinetic energy dissipation rate, the energy conservation equation, and the material composition conservation equation.

4. A device for analyzing the infrared stealth performance of a marine power exhaust system, characterized in that, include: The model building module is configured to build a geometric model of the chimney opening of the ship's power exhaust system based on a preset flow field calculation model. The fluid simulation module is configured to perform fluid simulation on the chimney section of the ship's power exhaust system based on the chimney window geometry model, and obtain the correspondence between the chimney window area and the average temperature at the chimney outlet. The fluid simulation on the chimney section of the ship's power exhaust system includes: obtaining the temperature distribution on the central interface of the chimney geometry under different chimney window areas; obtaining the temperature distribution on the surrounding walls of the chimney geometry under different chimney window areas; obtaining the temperature distribution at the rear of the chimney geometry under different chimney window areas; and obtaining the temperature distribution of the flue gas flow field at the rear of the chimney geometry under different chimney window areas. An infrared radiation brightness module is configured to calculate the infrared radiation brightness corresponding to different chimney opening areas based on the average temperature at the chimney outlet corresponding to different chimney opening areas, thus obtaining the correspondence between chimney opening area and infrared radiation brightness. Specifically, the infrared radiation brightness module is configured to treat the exhaust pipe at the chimney as a blackbody radiation source and calculate the infrared radiation brightness at the outlet of the exhaust pipe using the temperature field at the outlet of the exhaust pipe. The infrared radiation brightness L is calculated using the following formula: Where ε = 0.9, and the first radiation constant c1 = 3.7418 × 10⁻⁶. 4 W·μm 4 / cm 2 The second radiation constant c2 = 1.438 × 10 4 μm·K; The chimney window area selection module is configured to determine the chimney window area that maximizes the infrared stealth performance benefit of the ship's power exhaust system based on the correlation between the chimney window area, the average temperature at the chimney outlet, and the infrared radiation brightness. This determination includes: acquiring multiple sets of experimental data corresponding to the average temperature at the chimney outlet and the infrared radiation brightness for different chimney window areas; fitting the multiple sets of experimental data using data analysis software to obtain the correlation between the chimney window area and the average temperature at the chimney outlet, and the correlation between the chimney window area and the infrared radiation brightness; and, based on the correlation between the chimney window area and the average temperature at the chimney outlet, and the correlation between the chimney window area and the infrared radiation brightness, comprehensively evaluating the benefits of ship structural strength and chimney window area on infrared stealth performance, to determine the chimney window area that maximizes the infrared stealth benefit.

5. A computing device, comprising a processor and a memory storing program instructions, characterized in that, The processor is configured to, when running the program instructions, execute the method for analyzing the infrared stealth performance of a marine power exhaust system as described in any one of claims 1 to 3.

6. A storage medium storing program instructions, characterized in that, When the program instructions are executed, they perform the method for analyzing the infrared stealth performance of the marine power exhaust system as described in any one of claims 1 to 3.

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