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Computation of unsteady transonic flow over a fighter wing using a zonal Navier–Stokes/full-potential method

✍ Scribed by Olympio Achilles de Faria Mello; Lakshmi N. Sankar


Publisher
John Wiley and Sons
Year
1999
Tongue
English
Weight
175 KB
Volume
29
Category
Article
ISSN
0271-2091

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✦ Synopsis


An improved hybrid method for computing unsteady compressible viscous flows is presented. This method divides the computational domain into two zones. In the inner zone, the Navier -Stokes equations are solved using a diagonal form of an alternating-direction implicit (ADI) approximate factorisation procedure. In the outer zone, the unsteady full-potential equation (FPE) is solved. The two zones are tightly coupled so that steady and unsteady flows may be efficiently solved. Characteristicbased viscous/inviscid interface boundary conditions are employed to avoid spurious reflections at that interface. The resulting CPU times are about 60% of the full Navier -Stokes CPU times for unsteady flows in non-vector processing machines. Applications of the method are presented for a F-5 wing in steady and unsteady transonic flows. Steady surface pressures are in very good agreement with experimental data and are essentially identical to the full Navier -Stokes predictions. Density contours show that shocks cross the viscous/inviscid interface smoothly, so that the accuracy of full Navier -Stokes equations can be retained with significant savings in computational time.