An Experimental Investigation of Base Pressure on a Body of Revolution at High Thrust Levels and Free Stream Mach Numbers of 1.5 to 2.87

1970 ◽  
Author(s):  
Joseph C. Craft ◽  
Charles E. Brazzel
Keyword(s):  
Experimental Investigation ◽  
Free Stream ◽  
Base Pressure ◽  
Body Of Revolution ◽  
Mach Numbers ◽  
High Thrust

An Experimental Investigation of the Wake of an Axisymmetric Body with a Slanted Base

1983 ◽  
Vol 34 (1) ◽  
pp. 24-45 ◽  
Author(s):  
X.J. Xia ◽  
P.W. Bearman
Keyword(s):  
Drag Coefficient ◽  
Vortex Shedding ◽  
Free Stream ◽  
Sudden Change ◽  
Base Pressure ◽  
Wake Flow ◽  
Main Body ◽  
Angle Of Incidence ◽  
Slant Angle ◽  
Free Stream Turbulence

SummaryThe effect of base slant on the base pressure distribution, drag coefficient and vortex shedding characteristics of a model consisting of an axisymmetric main body with an ellipsoidal nose have been investigated for three fineness ratios; 3, 6 and 9. A sudden change in the drag coefficient and separated flow pattern is observed at a critical slant angle (for constant incidence) or at a critical angle of incidence (for a constant base slant angle). The tests confirm that the value of the maximum drag coefficient is extremely sensitive to angle of incidence. Measurements of the frequency of vortex shedding are presented and the structure of the wake is investigated using smoke visualization and hot-wire correlation measurements. The wake is found to be far less stable than that from a two-dimensional bluff body and the vortex structures are sometimes in-phase and sometimes out of phase across the wake. The effect of free-stream turbulence on this family of body shapes is observed to be different to that on three-dimensional blunt-faced bluff bodies. Free-stream turbulence is found to have a minimal effect on base pressure for slant angles giving a recirculating type near wake flow. When longitudinal vortices are present the addition of free-stream turbulence slightly reduces the magnitude of the peak suctions recorded on the base but has little effect on base drag.

Influence of base cavity on base pressure at subsonic and supersonic Mach numbers

2019 ◽  
Author(s):  
J. N. Murugan ◽  
Kiran Chutkey ◽  
S. B. Verma
Keyword(s):  
Base Pressure ◽  
Base Cavity ◽  
Mach Numbers

Blockage Corrections for Blunt-Based Bodies of Revolution

1968 ◽  
Vol 72 (696) ◽  
pp. 1058 ◽  
Author(s):  
W. A. Mair
Keyword(s):  
Correction Factor ◽  
Experimental Results ◽  
Base Pressure ◽  
Alternative Methods ◽  
Wind Tunnels ◽  
Maximum Diameter ◽  
Bodies Of Revolution ◽  
Blockage Correction ◽  
Mach Numbers ◽  
Experimental Values

Calvert has considered alternative methods of estimating the blockage corrections for blunt-based bodies of revolution in closed wind tunnels at low Mach numbers. His models were all of maximum diameter 152 mm, with an ellipsoidal nose section 203 mm long followed by a cylindrical afterbody. The ratio of overall length L to maximum diameter d varied from about 1.5 to 5.5. For each model the base pressure was measured in wind tunnels of two different sizes, so that the blockage correction factor e for the smaller tunnel could be derived for each model from the experimental results. These experimental values of e were compared with alternative theoretical estimates, using the methods given by Evans, Maskell and Pank-hurst and Holder.

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