Aircraft Combustor Nozzle Split for Lower nvPM Emissions
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Solution Overview
Problem
Gas turbine engines emit varying amounts of non-volatile particulate matter (nvPM) depending on the fuel type and operating parameters, necessitating adjustments in operating methods to reduce emissions.
Innovation Solution
The gas turbine engine is configured with a combustor featuring a plurality of fuel spray nozzles, including a first and second subset, where the first subset receives a higher fuel flow rate, and operates using sustainable aviation fuel (SAF) to optimize emissions indices.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional kerosene-based jet fuel is used, then the engine operates with established performance characteristics, but nvPM emissions increase and require operational adjustments
Solution Approach 1:
The patent applies parameter changes by adjusting operating parameters (such as fuel flow distribution between nozzle subsets, combustion chamber conditions, and turbine inlet temperature) when using SAF to optimize the combustion process and minimize nvPM emissions while maintaining engine performance
Solution Approach 2:
The patent implements dynamics by enabling the engine control system to dynamically adjust operating parameters based on the fuel type being used (traditional kerosene vs. SAF), allowing the engine to adapt its operation to minimize emissions for each fuel type
2Productivity
If fuel flow rate to first subset nozzles is increased, then combustion efficiency improves, but fuel distribution complexity increases
Solution Approach 1:
The patent applies segmentation by dividing the fuel spray nozzles into two distinct subsets (first subset and second subset) with different fuel flow rates, allowing optimized fuel distribution to different combustion zones while maintaining manageable system complexity through clear functional differentiation
Solution Approach 2:
The patent implements local quality by providing different fuel flow rates to different subsets of nozzles based on their specific locations and combustion requirements, optimizing combustion efficiency in different zones of the combustion chamber
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 reduces non-volatile particulate matter emissions, improving local air quality, reducing soot deposits, and minimizing contrail formation and radiative forcing, particularly at idle and cruise conditions.
Implementation Method 1
a plurality of fuel spray nozzles configured to inject fuel into the combustion chamber
Implementation Method 2
a combustor, comprising a combustion chamber and a plurality of fuel spray nozzles configured to inject fuel into the combustion chamber
Data Source
AI summary
A gas turbine engine for an aircraft. The gas turbine engine comprising: a combustor, comprising a combustion chamber and a plurality of fuel spray nozzles configured to inject fuel into the combustion chamber, wherein the plurality of fuel spray nozzles comprises a first subset of fuel spray nozzles and a second subset of fuel spray nozzles, wherein the combustor is operable in a condition in which each of the fuel spray nozzles of the first subset of fuel spray nozzles is supplied with fuel at a greater fuel flow rate than each of the fuel spray nozzles of the second subset of fuel spray nozzles, wherein a ratio of the number of fuel spray nozzles in the first subset of fuel spray nozzles to the number of fuel spray nozzles in the second subset of fuel spray nozzles is in the range of 1:2 to 1:5. An MTO nvPM emissions index ratio-modified fuel flow is defined as:EImaxTO,SAFEImaxTO,FF×Wf,maxTOwhere: EImaxTO,SAF is the system loss corrected nvPM emissions index in mg/kg of the gas turbine engine when operating at around 100% available thrust for given operating conditions if a fuel provided to the plurality of fuel spray nozzles comprises a sustainable aviation fuel (SAF); EImaxTO,FF is the system loss corrected nvPM emissions index in mg/kg of the gas turbine engine when operating at around 100% available thrust for the given operating conditions if a fuel provided to the plurality of fuel spray nozzles is a fossil-based hydrocarbon fuel; and Wf,maxTO is the mass flow rate of fuel provided to the plurality of fuel spray nozzles in kg/s when the gas turbine engine is operating at around 100% available thrust for the given operating conditions. The MTO nvPM emissions index ratio-modified fuel flow of the gas turbine engine in kg/s is less than 2. The gas turbine engine is configured to provide fuel comprising a SAF to the plurality of fuel spray nozzles. Also disclosed is a method of operating the gas turbine engine.