SIAM Journal on Control and Optimization, Vol.45, No.4, 1165-1197, 2006
Domain dependence of solutions to compressible Navier-Stokes equations
The minimization of the drag functional for the stationary, isentropic, compressible Navier-Stokes equations (NSE) in three spatial dimensions is considered. In order to establish the existence of an optimal shape, the general result on compactness of families of generalized solutions to the NSE is established within in the framework of the modern theory of nonlinear PDEs [P. L. Lions, Mathematical Topics in Fluid Dynamics. Vol. 2. Compressible Models, Oxford University Press, Clarendon Press, New York, 1998], [E. Feireisl, Dynamics of Viscous Compressible Fluids, Oxford University Press, Oxford, UK, 2004]. The family of generalized solutions to the NSE is constructed over a family of admissible domains U-ad. Any admissible domain ohm = B\S contains an obstacle S, e.g., a wing pro. le. Compactness properties of the family of admissible domains in the form of the condition (H-Omega) is imposed. Roughly speaking, the condition (H-Omega) is satisfied, provided that for any sequence of admissible domains {Omega(n)} subset of U-ad there is a subsequence convergent both in Hausdorff metrics and in the sense of Kuratowski and Mosco. The analysis is performed for the adiabatic constant gamma > 1 in the pressure law p(p) = p(gamma) and it is based on the technique used in [P.I. Plotnikov and J. Sokolowski, Comm. Math. Phys., 258 (2005), pp. 567-608] in the case of discretized NSE. The result is a generalization to the stationary equations with gamma > 1 of the results obtained in [E. Feireisl, A. H. Novotny, and H. Petzeltova, Math. Methods Appl. Sci., 25 (2002), pp. 1045-1073], [E. Feireisl, Appl. Math. Optim., 47 (2003), pp. 59-78] for evolution equations within the range gamma > 3/2 for the adiabatic ratio.