Drag Measurements of Upswept Afterbodies and Analytical Study on Axisymmetric Separation
Report Number: AFFDL TR 73-153
Author(s): Hahn, Mansop, Rubbert, Paul E., Nark, T. C., Brune, Gunter W.
Corporate Author(s): Boeing Airplane Company
Laboratory: Air Force Flight Dynamics Laboratory
Date of Publication: 1974-02
Pages: 70
Contract: F33615-73-C-3037
DoD Project: 1476
DoD Task: 147601
Identifier: AD0778819
Abstract:
The drag of several afterbodies was measured for various upsweep angles and presented as a function of three afterbody geometric parameters. Carpet plots were used to empirically predict the afterbody drag increment. Although present test results were obtained for a single forebody configuration incorporating a low wing position and a 2 degree wing incidence angle, agreement between the present results and other available experimental data appeared to be reasonable. A theoretical approach to the problem of predicting three-dimensional separated flow was developed that allows application of the best numerical procedure for each type of flow encountered. Viscous separated flow, boundary layers, and inviscid flow are numerically matched by a procedure that is conceptually simple and economical. The method was explored for the model problem of axisymmetric laminar separated flow about an ellipsoid, and rapi convergence to an accurately matched solution including drag prediction was demonstrated. A feasibility study of applying the method to the problem of three-dimensional separation from swept wings was conducted.
Provenance: Bombardier/Aero
Author(s): Hahn, Mansop, Rubbert, Paul E., Nark, T. C., Brune, Gunter W.
Corporate Author(s): Boeing Airplane Company
Laboratory: Air Force Flight Dynamics Laboratory
Date of Publication: 1974-02
Pages: 70
Contract: F33615-73-C-3037
DoD Project: 1476
DoD Task: 147601
Identifier: AD0778819
Abstract:
The drag of several afterbodies was measured for various upsweep angles and presented as a function of three afterbody geometric parameters. Carpet plots were used to empirically predict the afterbody drag increment. Although present test results were obtained for a single forebody configuration incorporating a low wing position and a 2 degree wing incidence angle, agreement between the present results and other available experimental data appeared to be reasonable. A theoretical approach to the problem of predicting three-dimensional separated flow was developed that allows application of the best numerical procedure for each type of flow encountered. Viscous separated flow, boundary layers, and inviscid flow are numerically matched by a procedure that is conceptually simple and economical. The method was explored for the model problem of axisymmetric laminar separated flow about an ellipsoid, and rapi convergence to an accurately matched solution including drag prediction was demonstrated. A feasibility study of applying the method to the problem of three-dimensional separation from swept wings was conducted.
Provenance: Bombardier/Aero