Convection-Cooled Leading Edge for Hypersonic Vehicles (3rd Generation)

3rd Generation Prototype, Entirely Convectively Cooled

In 1995 Micro Cooling Concepts' employees completed a contract to develop a prototype leading edge for a generic hypersonic vehicle. This leading edge represented the third generation of their leading edge designs, and the first leading edge that was completely internally cooled. The program served as a foundation for fourth generation leading edges subsequently sponsored by USAF/WL and NASA/Langley. The third generation development effort is described below.

Problem

• Hypersonic Vehicle Leading Edges are Exposed to Severe Heating Environments

  • Steady-State Heating Up to 3.5 kW/cm**2
  • Transient (Shock-on-Lip) Heating > 35 kW/cm**2
  • Active Cooling Required; Transpiration/Film Cooling Undesirable

• Hydrogen-Based Cooling Systems are Limited in Capability

  • Hydrogen Fuel is Only Available Coolant
  • Hydrogen has Poor Heat Transfer Properties

Accomplishments

• Successfully Fabricated Glidcop Leading Edge Prototype

  • Model Was 5 cm in Span, w/0.25 cm Nose Radius and 6 Degree Wedge Half-Angle
  • Model Incorporated 3500 Microchannel Cooling Circuits
  • Each Microchannel was 50 microns x 500 microns in Cross-section

• Bench Tested Protoype Model

  • Torch Tests Show Excellent Flow and Heat Transfer Performance
  • Test Results Closely Match Predictions

Unique Capabilities

Capable of Operating at a Steady-State Heat Flux of 11.5 kW/cm**2 Using Gaseous Hydrogen

• Low Pumping Powers Required
• High-Strength, Hydrogen-Compatible Construction