Pressure drag and lift contributions for blunted forebodies of fineness ratio 2.0 in transonic flow (M∞ ≤ 1.4).
Abstract:ESDU 89033 presents axial and normal pressure force coefficient data obtained from a computed solution of the Euler equations for inviscid flow about spherically blunted tangent ogive and cone forebodies followed by a cylindrical afterbody in the Mach number range of 0.7 to 1.4. It is found that there is a an optimum blunting ratio (ratio of the blunted nose diameter to the afterbody diameter) for which for a given Mach number and angle of attack the axial pressure force is a minimum. Charts show the variation of axial and normal pressure force coefficients around the optimum blunting for angles of attack up to 10 degrees, and axial pressure force coefficient (which is equivalent to the wave drag) at zero incidence. The derivation of the results is discussed, and examples compare forebody pressure distributions and force coefficients with those obtained in wind-tunnel tests, so providing guidance on the expected accuracy of the calculations.
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