Rotary Engine Pilot Subchambers Combustion
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Solution Overview
Problem
Rotary internal combustion engines, particularly Wankel engines, face inefficiencies in combustion due to the limited effectiveness of single pilot subchambers in igniting fuel and transferring it to the main combustion chamber, leading to suboptimal fuel-air mixture stratification and combustion efficiency.
Innovation Solution
The implementation of at least two pilot subchambers in parallel fluid communication with the combustion chambers, where a pilot quantity of fuel is ignited and directed into the combustion chamber through transfer holes that partially restrict the flow, enhancing the ignition of the main fuel quantity and achieving a lean fuel-air mixture.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single pilot subchamber is used for fuel ignition and transfer, then the device complexity is reduced, but the combustion efficiency deteriorates
Solution Approach 1:
The single pilot subchamber is divided into multiple pilot subchambers (at least two) that operate in parallel. Each pilot subchamber receives pilot fuel through separate injectors and ignites fuel independently, then transfers the ignited fuel to the main combustion chamber through respective transfer holes. This segmentation improves combustion efficiency and fuel-air mixture stratification while maintaining manageable system complexity through modular architecture.
2Reliability
If multiple pilot subchambers are used in parallel, then the combustion efficiency is improved, but the device complexity increases
Solution Approach 1:
The system is segmented into multiple independent pilot subchambers that can be added or removed based on performance requirements. Each subchamber is a self-contained module with its own fuel injector, ignition source, and transfer holes, allowing for scalable complexity adjustment.
Solution Approach 2:
Pilot fuel is injected and ignited in the pilot subchambers before the main fuel is introduced into the combustion chamber. This preliminary ignition creates a ready source of ignited fuel that enhances the combustion of the main fuel quantity, improving overall combustion efficiency without requiring complex real-time control systems.
3Manufacturing precision
If transfer holes are used to direct ignited fuel from pilot subchambers to combustion chamber, then the fuel-air mixture stratification is improved, but the fluid flow is restricted
Solution Approach 1:
The transfer holes are strategically positioned and sized to create localized regions of high fuel concentration within the combustion chamber. This local quality enhancement allows for stratified combustion where the ignited pilot fuel creates rich zones that enhance combustion of the surrounding leaner fuel-air mixture, improving overall combustion efficiency while maintaining adequate total fuel flow.
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
This configuration improves combustion efficiency by allowing for a stratified fuel-air mixture and optimized fuel ignition, leading to enhanced power output and reduced emissions in rotary internal combustion engines.
Implementation Method 1
The pilot fuel is ignited in the pilot subchamber and transferred to the main combustion chamber so as to ignite the fuel injected therein by a main fuel injector
Data Source
AI summary
A rotary engine including at least two pilot subchambers each in parallel fluid communication with the internal cavity, so that each pilot subchamber is in fluid communication with the combustion chambers as the rotor rotates. Each of the at least two pilot subchambers in fluid communication with a corresponding pilot fuel injector. At least one ignition source is configured for igniting fuel in the pilot subchambers. A compound engine assembly and a method of combusting fuel in a rotary engine are also discussed.