Rotating Detonation Combustion Pilot Burner for Engine Stability
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current propulsion systems, such as gas turbines, ramjets, and scramjets, face challenges in stabilizing the combustion process, particularly in gas turbine augmentor/afterburner or inter-turbine burner systems, where further improvements in thermodynamic efficiency and combustion stability are desired.
Innovation Solution
A Brayton cycle engine design with a longitudinal wall defining a gas flowpath and an inner wall assembly creating a rotating detonation combustion region upstream, which acts as a pilot burner to stabilize and improve the combustion process by modulating fuel injection between the detonation and conventional combustion regions, allowing operation over a range of dynamic pressures.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional deflagrative combustion systems are used in gas turbines, ramjets, and scramjets, then the systems have reached high thermodynamic efficiency through steady improvements, but combustion stability remains difficult to improve further
Solution Approach 1:
The combustion system is segmented into two distinct regions: a detonation combustion region upstream where rotating detonation waves occur, and a conventional combustion region downstream. This segmentation allows each region to perform its specialized function - the detonation region provides stability and ignition, while the downstream region handles main combustion, thereby improving overall combustion stability without excessive complexity
Solution Approach 2:
The rotating detonation combustion region acts as an intermediary or pilot burner between the fuel injection system and the main conventional combustion chamber. It pre-conditions the fuel-oxidizer mixture and provides stable ignition sources, serving as a mediator that bridges the gap between fuel injection and main combustion, thereby enhancing combustion stability
2Power
If fuel injection is increased to improve combustion performance, then combustion intensity increases, but combustion stability deteriorates due to improper fuel/oxidizer mixing ratios
Solution Approach 1:
Different fuel injection strategies are applied to different regions: the upstream detonation combustion region receives a first flow of fuel optimized for detonation chemistry and stoichiometry, while the downstream conventional combustion region receives a second flow of fuel optimized for sustained combustion. This local differentiation of fuel quality and injection timing allows high combustion intensity in the downstream region while maintaining stability through the controlled detonation region
Solution Approach 2:
The system changes key combustion parameters by transitioning from uniform deflagrative combustion to a two-stage process with detonation (supersonic combustion) in the upstream region and conventional subsonic combustion downstream. This parameter change enables higher overall combustion intensity while the controlled detonation process maintains stability through precise fuel-oxidizer ratio management in each region
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 engine achieves improved combustion stability and performance by using a rotating detonation combustion region as a pilot burner, enabling operation across varying dynamic pressures and enhancing the efficiency of ramjet, scramjet, and gas turbine engines.
Implementation Method 1
A rotating detonation combustion region is defined upstream of the inner wall assembly. A first flow of fuel is provided to the rotating detonation combustion region
Implementation Method 2
The inner wall assembly captures a portion of a flow of oxidizer and defines a rotating detonation combustion region
Data Source
AI summary
A Brayton cycle engine including a longitudinal wall extended along a lengthwise direction. The longitudinal wall defines a gas flowpath of the engine. An inner wall assembly is extended from the longitudinal wall into the gas flowpath. The inner wall assembly defines a detonation combustion region in the gas flowpath upstream of the inner wall assembly.