Variable Orifice Jet for Turbine Engine Fuel Injection
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Solution Overview
Problem
Turbine engine fuel injectors face challenges with low fuel pressure, leading to inadequate fuel injection depth and atomization, as existing systems struggle to maintain optimal fuel mixing and spray patterns under varying pressure conditions.
Innovation Solution
A variable orifice jet system that adjusts its orifice area in response to changing fuel pressure, using a flexible body and pintle configuration to ensure consistent fuel spray patterns by increasing or decreasing the orifice area based on pressure changes, thereby maintaining efficient fuel injection and atomization.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If fuel pressure is low, then fuel injection cost is reduced, but fuel mixing quality deteriorates due to insufficient injection depth and atomization
Solution Approach 1:
The orifice area is made variable through a flexible body that dynamically adjusts its shape in response to fuel pressure changes. At low fuel pressure, the flexible body contracts to reduce the orifice area, increasing fuel velocity and injection depth. At high fuel pressure, the flexible body expands to increase the orifice area, preventing excessive injection depth and maintaining proper atomization. This dynamic adaptation resolves the contradiction between fuel pressure and fuel mixing quality.
Solution Approach 2:
The system changes the physical parameter of orifice area based on fuel pressure conditions. The flexible body's elasticity allows the orifice area to automatically vary with pressure, transforming a static parameter into a dynamic one that adapts to operating conditions, thereby maintaining consistent fuel spray characteristics across varying pressure levels.
2Productivity
If orifice area is increased to improve fuel flow, then fuel injection rate increases, but injection depth decreases leading to poor mixing
Solution Approach 1:
The orifice area dynamically adjusts based on fuel pressure rather than being fixed. When pressure is low, the smaller orifice area maintains injection depth while still providing adequate flow. When pressure is high, the larger orifice area increases flow rate while preventing excessive depth. This dynamic adjustment resolves the trade-off between injection rate and injection depth.
3Manufacturing precision
If orifice area is decreased to increase injection depth, then fuel mixing improves, but fuel injection rate decreases
Solution Approach 1:
The system changes the orifice area parameter in response to pressure conditions. At low pressure, a smaller area maintains depth and mixing quality while preserving flow rate. At high pressure, a larger area increases injection rate while preventing excessive depth that would cause poor atomization. This parameter adaptation resolves the contradiction between mixing quality and injection rate.
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 variable orifice jet system ensures optimal fuel mixing and spray patterns across varying fuel pressures, enhancing engine thrust and reducing manufacturing, assembly, and maintenance costs by maintaining a consistent fuel spray pattern independent of pressure fluctuations.
Implementation Method 1
a flexible body, which defines an inner periphery of an orifice and has an internal volume that changes based on pressure of fuel contained within the variable volume member
Data Source
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AI summary
A fuel delivery system is provided for a turbine engine. This fuel delivery system includes a variable orifice jet 56 configured to spray fuel received from a spray bar fuel conduit 54. The variable orifice jet 54 includes a flexible body 60 and a pintle 62 that extends through a sidewall of the flexible body 60. An area of an orifice 86 between the sidewall and the pintle 62 is variable.