Tall Vortex Generators for Supersonic Engine Pressure Distortion
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Solution Overview
Problem
Conventional supersonic aircraft propulsion systems experience distortion in stagnation pressure due to the buildup of a thick boundary layer on internal surfaces, leading to adverse impacts on engine operability and performance, with existing solutions either adding cost, complexity, or failing to effectively reduce boundary layer thickness and stagnation pressure distortion.
Innovation Solution
The use of tall vortex generators positioned on the center body, exceeding 75% of the boundary layer thickness, which generate vortices that propagate outside the boundary layer, redistributing airflow to reduce radial distortion in stagnation pressure by moving high-velocity air towards the engine core and low-velocity air away from it.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stress or pressure
If an elongated compression surface is used to improve pressure recovery, then pressure recovery is improved, but a thick boundary layer builds up on internal surfaces causing stagnation pressure distortion
Solution Approach 1:
The patent extracts the harmful boundary layer air from the main airflow path by using vortex generators to create vortices that transport boundary layer air away from the compression surface and into the mainstream flow, thereby removing the source of stagnation pressure distortion
Solution Approach 2:
Vortex generators act as intermediary structures that mediate between the boundary layer and mainstream flow, creating vortices that facilitate the mixing and redistribution of air masses, thereby eliminating stagnation pressure distortion without compromising pressure recovery
2Stability of the object's composition
If vortex generators of modest height (20-40% of boundary layer thickness) are positioned on the center body, then the boundary layer remains attached to the surface, but the boundary layer thickness is not reduced and stagnation pressure distortion persists
Solution Approach 1:
The patent changes the critical parameter of vortex generator height from the conventional 20-40% of boundary layer thickness to greater than 75% of boundary layer thickness. This parameter change transforms the vortex generators from merely stabilizing the boundary layer to actively redistributing flow and eliminating stagnation pressure distortion
3Object-affected harmful factors
If bleed systems are used to extract the boundary layer from the airflow, then boundary layer thickness is reduced, but cost, complexity, and weight of the propulsion system increase
Solution Approach 1:
The vortex generators passively generate vortices that automatically transport boundary layer air away from the surface and into the mainstream flow without requiring any active control systems, power sources, or complex mechanical components, thereby achieving boundary layer management through self-service
Solution Approach 2:
The patent replaces the active mechanical bleed system with passive vortex generators that use aerodynamic forces to achieve boundary layer control, substituting a complex mechanical system with a simpler aerodynamic solution
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 approach enhances engine performance by reducing radial distortion in airflow stagnation pressure, improving thrust generation and overall engine efficiency by ensuring a more homogeneous airflow distribution across the engine face.
Implementation Method 1
a first vortex generator disposed on the center body. The first vortex generator extends a first height above the center body... a second vortex generator disposed on the center body. The second vortex generator extends a second height above the center body... generate vortices that propagate outside the boundary layer
Implementation Method 2
The vortices created by the plurality of vortex generators cause an up-wash and a down-wash that moves a high-velocity portion of the airflow radially inward toward the center body and that moves a low-velocity portion of the airflow radially outward and away from the center body
Data Source
AI summary
An arrangement for use with a propulsion system for a supersonic aircraft includes a center body configured for coupling to an inlet and to support a boundary layer formed when the supersonic aircraft is flown at a predetermined altitude supersonic speed. The arrangement further includes a first vortex generator disposed on the center body. The first vortex generator extends a first height above the center body. The arrangement still further includes a second vortex generator disposed on the center body. The second vortex generator extends a second height above the center body, the second height being greater than the first height. The first height and the second height are greater than approximately seventy-five percent of a thickness of the boundary layer proximate a location of the first vortex generator and the second vortex generator, respectively, when the aircraft if flown at the predetermined altitude and the predetermined speed.