Publication Date:
2019-07-13
Description:
Experimental data from several model inlets are used to generate two parameters which are related to the limit of operation for inlet flow separation. One parameter, called the diffusion ratio, is the ratio of the peak velocity on the inlet surface to the velocity at the diffuser exit and is related to the boundary-layer separation at low throat Mach numbers. The other parameter, the peak Mach number on the inlet surface, is related to the separation at high throat Mach numbers. These parameters are easily calculated from potential flow solutions and thus can be used as a design tool in screening proposed inlet geometries. An illustrative example of an application to an inlet design study for a tilt nacelle VTOL airplane is presented. The value of contraction ratio required to meet the operating requirements yet allow the inlet to remain free of separation as indicated by the two separation parameters is shown.
Keywords:
AIRCRAFT DESIGN, TESTING AND PERFORMANCE
Type:
NASA-TM-73709
,
Propulsion Conf.; Jul 11, 1977 - Jul 13, 1977; Orlando, FL; United States
Format:
application/pdf
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