The efficacy of large-eddy simulation ~LES! with wall modeling for complex turbulent flows is assessed by considering turbulent boundary-layer flows past an asymmetric trailing-edge. Wall models based on turbulent boundary-layer equations and their simpler variants are employed to compute the instantaneous wall shear stress, which is used as approximate boundary conditions for the LES. It is de...

A series of supersonic wind tunnel tests on an ogive-cylinder body were performed to investigate the pressure distribution, the boundary layer profiles, and the flow visualization at various angles of attack. All tests were conducted in the trisonic wind tunnel of the Imam Hossein University. The theoretical shock angle at different model positions compared well with those we obtained via Schi...

A series of supersonic wind tunnel tests on an ogive-cylinder body were performed to investigate the pressure distribution, the boundary layer profiles, and the flow visualization at various angles of attack. All tests were conducted in the trisonic wind tunnel of the Imam Hossein University. The theoretical shock angle at different model positions compared well with those we obtained via Schi...

Effective delay of turbulent boundary layer separation could be achieved via closed-loop control. Constructing such a system requires that sensor data be processed, real-time, and fed into the controller to determine the output. Current methods for detection of turbulent boundary layer separation are lacking the capability of localized, fast and reliable identification of the boundary layer sta...

This study investigates linear and nonlinear dynamic LES and unified RANS-LES models obtained by stochastic analysis regarding the simulation of the atmospheric boundary layer. The advantages of dynamic LES methods are their accuracy, the ability to account for anisotropy and backscatter, and their computational stability. The advantage of unified RANS-LES models is their ability to provide res...

In this work, we study the characteristics of a stably stratified atmospheric boundary layer using large-eddy simulation (LES). In order to simulate the stable planetary boundary layer, we developed a modified version of the two-part subgrid-scale model of Sullivan et al. This improved version of the model is used to simulate a highly cooled yet fairly windy stable boundary layer with a surface...

Entrainment is the process whereby miscible fluid is exchanged across a density interface bounding a region of turbulent flow [17]. It is of central importance in governing the dynamics of the atmospheric boundary layer (ABL) top. In the exchange process, relatively quiescent fluid is engulfed by turbulent motions penetrating across the interface and is subsequently mixed into the turbulent reg...