Throat Corner Scoops for Mixed Compression Inlet Stability
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Solution Overview
Problem
High-speed aircraft engine inlets with exotic shapes face performance losses due to vorticity and boundary layer separation at acute angles, and mixed compression inlets can experience 'unstart' and inefficient airflow utilization, particularly in non-axi-symmetric designs.
Innovation Solution
The implementation of throat corner scoops within the mixed compression inlets to capture and remove low-pressure airflow, enhancing inlet stability and providing additional airflow for auxiliary systems, while addressing corner flow issues and acute angle geometries.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If exotically-shaped mixed compression inlets are used to reduce drag at supersonic speeds, then aerodynamic performance is improved, but vorticity and boundary layer separation occur at acute angles causing flowfield distortion and engine performance loss
Solution Approach 1:
The patent extracts the harmful corner flow and boundary layer separation by introducing throat corner scoops that capture and remove this low-pressure airflow from the main duct before it can cause flowfield distortion and engine performance loss
Solution Approach 2:
The patent applies local quality by placing throat corner scoops specifically at the acute angle corners where boundary layer separation occurs, while maintaining the exotically-shaped duct geometry in other regions to preserve aerodynamic efficiency
2Stability of the object's composition
If throat bleed systems with shock traps and cowl slots are used to remove boundary layer, then terminal shock stability is improved, but pressure recovery is reduced and distortion increases
Solution Approach 1:
The patent extracts the boundary layer removal function from traditional shock traps and cowl slots and relocates it to throat corner scoops positioned at acute angles, where the scoops capture corner flow directly without disrupting the main duct pressure recovery
Solution Approach 2:
The patent transitions from two-dimensional bleed systems (shock traps, cowl slots) to three-dimensional throat corner scoops that exploit the corner region geometry, enabling boundary layer removal while preserving pressure recovery through volumetric flow capture
3Object-generated harmful factors
If low energy air is captured in shock traps, then boundary layer removal is achieved, but the air is exhausted overboard due to insufficient energy for utility flow
Solution Approach 1:
The patent converts the previously wasted low-energy corner flow into useful utility flow by positioning throat corner scoops to capture this airflow and redirect it through utility outlets, transforming a harmful boundary layer effect into a beneficial resource for aircraft systems
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 solution improves airflow stability and efficiency, reduces engine performance losses, and enables the viability of advanced, non-axi-symmetric inlet designs by removing low-pressure airflow and providing utility flow, thus enhancing overall engine performance and integration with airframe systems.
Implementation Method 1
They are positioned in a region otherwise prone to generate low pressure airflow. The throat scoops capture and remove the low pressure airflow from the bulk stream
Data Source
AI summary
A system, method, and apparatus for throat corner scoop offtake for mixed compression inlets for high speed aircraft engine applications is disclosed. The throat corner scoops are small air intakes located inside the large mixed compression inlet. They are positioned in a region otherwise prone to generate low pressure airflow. The throat corner scoops capture and remove the low pressure airflow from the bulk stream that is passed on to the engine. This location also provides inlet stability enhancement, and the airflow is used on the auxiliary systems.