Accession Number:
AD0767712
Title:
Experimental Investigation of an External Aerodynamic Diffuser,
Descriptive Note:
Corporate Author:
WEST VIRGINIA UNIV MORGANTOWN DEPT OF AEROSPACE ENGINEERING
Personal Author(s):
Report Date:
1971-04-01
Pagination or Media Count:
96.0
Abstract:
Improvement in the thrustpower ratio for shrouded propellers and fan-in-wing units, which are widely used for VSTOL aircraft propulsion, can be achieved by using an external aerodynamic diffuser during hover. Large diffuser divergence angles are required which necessitate a technique of controlling the flow separation from the internal diffuser wall. The purpose of this experimental investigation was to obtain a correlation between experimental and analytical prediction of performance improvement in order to generate a design technique for optimization of external diffusion, and investigate the potential of several techniques which offer a method of forcing the flow to diffuse externally. A static test facility for measuring the external flow field and the thrust of the model was constructed. All tests were performed with uniform, axial flow at the diffuser inlet. Two-dimensional tests were conducted employing either turning vanes, coanda effect, or rotating cylinder walls. Axisymmetric tests were performed using boundary layer control by suction or blowing. Modified author abstract
Descriptors:
Subject Categories:
- Aerodynamics
- VSTOL
- Jet and Gas Turbine Engines