ESDU 10016:2011

$163.80

Drag of a Rectangular Planform Cavity in a Flat Plate with a Turbulent Boundary Layer for Mach Numbers Up to 3 – Part III: Effect of Doors

Published By	Publication Date	Number of Pages
ESDU	2011-09-01	80

Guaranteed Safe Checkout

Category: ESDU

If you have any questions, feel free to reach out to our online customer service team by clicking on the bottom right corner. We’re here to assist you 24/7.
Email:[email protected]

Description

This Data Item is the third in the series of Items concerned
with the prediction of the drag of rectangular planform cavities
for Mach numbers up to 3. ESDU 00006 (Part I) deals with cavities
having closed flow, and ESDU 00007 (Part II) is for cavities having
open or transitional flow. Those Items are only applicable to
cavities without doors, so the present Data Item (Part III)
completes the series with the provision of methods for the
prediction of the drag of a pair of equal width doors open at 90°,
typical of weapons bay applications.

The prediction methods use data (where available) from the ESDU
Aerodynamics Series, and involve planar doors at subsonic or
supersonic speeds. The effects of three types of door leading and
trailing edges are considered: straight (i.e. unswept) with either
square edges, chamfered (i.e. wedge or chiselled) edges or
sawtoothed with chamfered edges. A summary of the door drag
prediction components is given, including tables of the components
and references to the relevant prediction equations. The way in
which door drag is used in the determination of the total drag
coefficient due to the presence of a rectangular cavity with doors
open at 90° is also given.

The drag prediction methods for cavity doors were developed
using wind-tunnel data for flat plates at zero angle of attack in
uniform flows. As with the methods for the drag of cavities without
doors (ESDU 00006 and ESDU 00007), in order to apply the methods to
a practical situation in which a cavity with a pair of doors open
at 90° is in a non-uniform flow, an artifice employed in the
application of excrescence drag data is used, see ESDU 90029. With
regard to base drag, ESDU 10017 provides a guide to the
effectiveness of the various types of trailing-edge device used to
alleviate the drag of blunt trailing edges. The possible use and
appropriateness of such devices for weapons bay doors is discussed.
In order to gain some appreciation of the effects on drag of the
different door leading-edge and trailing-edge geometries, a set of
examples based on the cavity in Example 2 of ESDU 00006 at
M₁ = 0.8 and 2.0 is given.

The door drag prediction methods use available data from the
ESDU Aerodynamics Series, but there are three main areas where
there are no suitable ESDU data, and they are dealt with in
Appendices A to C. Those areas concern the pressure drag due to
blunt leading edges (Appendix A), blunt trailing edges (Appendix B)
and chamfered (wedge) leading edges (Appendix C) of flat plates at
subsonic speeds.

Additional information