Multimode Gas Turbine Fuel Injection with Rotating Air Deflector
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Solution Overview
Problem
Existing multimode injection devices for combustion chambers in turbojet engines face challenges in reducing polluting emissions at high engine speeds, particularly during takeoff, due to inefficiencies in peripheral spraying.
Innovation Solution
A multimode injection device featuring a peripheral spray system with an annular distribution chamber and a rotating air deflector with fins, which directs air towards fuel jets from regularly distributed ejection holes, and internally tapered walls to optimize fuel distribution and reduce axial size, enhancing combustion efficiency and reducing pollution.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Quantity of substance
If a peripheral distribution chamber with multiple ejection holes is used, then the quantity of substance (fuel distribution) is improved, but the axial size of the device increases
Solution Approach 1:
The distribution chamber is nested within the deflector structure, with the deflector's internal cavity forming the distribution chamber space. This nesting allows the fuel distribution function to be integrated into the existing deflector volume without adding axial length, resolving the contradiction between quantity of substance and axial size.
Solution Approach 2:
The invention transitions from a traditional axial fuel distribution approach to a radial distribution approach by using the deflector's rotational symmetry. Fuel is distributed through multiple ejection holes arranged circumferentially, utilizing the radial dimension to achieve quantity of substance while maintaining compact axial size.
2Stability of the object's composition
If air is directed towards fuel jets to improve mixing, then the homogeneity of air-fuel mixture is improved, but the device complexity increases
Solution Approach 1:
The deflector structure serves multiple functions simultaneously: it directs air towards fuel jets for mixing, provides structural support for the distribution chamber, and creates the rotational flow pattern. This multi-functionality improves homogeneity of air-fuel mixture without increasing device complexity, as one component performs multiple roles.
Solution Approach 2:
The deflector utilizes the existing rotational motion of the combustion chamber to create air flow patterns that automatically direct air towards fuel jets. The system self-regulates the air-fuel mixing process through the rotational dynamics, improving homogeneity without requiring additional control mechanisms or complex device additions.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution improves the homogeneity of the air-fuel mixture, leading to better combustion and reduced pollution, while minimizing the axial bulk of the injection device, thereby effectively limiting emissions at high engine speeds.
Implementation Method 1
a rotating air deflector, annular, installed radially externally with respect to said plurality of ejection holes, in that said deflector comprises fins defining channels of air ejection
Implementation Method 2
said annular deflector comprises two internally tapered walls, coaxial, respectively upstream and downstream, with a taper directed downstream
Data Source
Figure 1
Figure 2~6
Figure 4~7
AI summary
The device includes a peripheral spraying system having a plurality of regularly circumferentially distributed fuel ejection holes (31) and an annular gyratory air deflector comprising air ejection channels (36) such that, for each fuel ejection axis defined by an ejection hole (31), there is a corresponding air ejection channel of which at least the innermost radial part has a median (M) substantially intersecting this fuel ejection axis.