The unsteady viscous flow in the vicinity of an axisymmetric stagnation point of an infinite moving cylinder with time-dependent axial velocity is investigated. The impinging free stream is steady with a strain rate k. An exact solution of the Navier-Stokes equations is derived in this problem. A reduction of these equations is obtained by use of appropriate transformations. The general self-si...

The parallel numerical solution of the Navier-Stokes equations with the sparse grid combination method was studied. This algo-rithmic concept is based on the independent solution of many problems with reduced size and their linear combination. The algorithm for 3-dimensional problems is described. Its parallel implementation on an IBM SP2 and a cluster of 16 HP workstations is discussed.

We consider the Navier–Stokes system in a bounded domain with a smooth boundary. Given a time-dependent solution and an arbitrary open subset of the boundary, we prove the existence of a boundary control, supported in the given subset, that drives the system to the given solution in finite time.

analysis of the flow passing cylindrical obstacles is one of the basic issues in fluid dynamics and is of great importance. many surveys have been conducted to investigate the velocity field in potential and viscous flows, as a basis for finding pressure field, and investigation of forces exerted by fluid on obstacles such as uplift and drag forces in different flow regimes. since the nature of...

We present evidence that the problem of breakdown/blowup of smooth solutions of the Euler and Navier-Stokes equations, is closely related to Hadamard’s concepts of wellposedness and illposedness. We present a combined criterion for blowup, based on detecting increasing L2-residuals and stability factors, which can be tested computationally on meshes of finite mesh size. 1 The Clay Navier-Stokes...