Transition modeling represents one of the key challenges in computational fluid dynamics (CFD). While numerical efforts were traditionally devoted to either improving Reynolds-averaged Navier-Stokes (RANS)-based turbulence modeling or developing scale-resolving simulations, cautious attention has been recently given to field inversion and machine learning techniques. This paper discusses an updated development of field inversion model for transitional flows based on k-ω shear stress transport ( SST) model using the continuous adjoint approach, instead of the typical discrete adjoint method. The original model is modified by multiplying the production term of the turbulent kinetic energy equation by a spatially varying discrepancy function η(x). The adjoint equations and the relevant boundary conditions are specifically derived and integrated in OpenFOAM. The present model is validated using two zero pressure-gradient and four non-zero pressure-gradient from flow-over-flat-plate T3-series test cases. The gradient descent method is employed in the optimization process to minimize the discrepancy in the calculated shear stress. The inferred solution indicates a smooth transition to turbulence at the reported critical Reynolds numbers. The optimized model significantly improves the predictions of skin-friction coefficients, originally incorporated in the objective function. To demonstrate the usefulness of the present approach, the investigation is further extended to determine both velocity and shear Reynolds-stress profiles, which to our knowledge has not been reported before. Furthermore, a reduction in the percentage error from 50.2% to 7.3% is well observed in the predicted boundary layer thickness considering the laminar regime in the T3C5 test case.
The nose is considered an important structure in the face from both the cosmetic and functional point of view. It is the most projecting part in the face; hence any disfigurement is obvious and cannot be hidden. Skin defects may occur due to many reasons including post traumatic and post ablative following excision of skin cancer. There are various methods for coverage according to the reconstructive ladder. However, due to its importance, local flaps are always preferable to skin grafts as this produces like with like replacement including good padding with well vascularized tissue, pliable coverage, sensate tissue with better contouring, texture and color matching when compared to skin grafting. In this paper, although many flaps are described in literature, but most defects of the nose can be best closed by three common flaps used in this area. These flaps are reviewed including forehead flap, nasolabial flap and bilobed flap with the authors' personal experience in this field. Ten cases were operated upon by the authors in Kasr Al-Aini Hospital between February 2016 to July 2016 and followed-up for the following six months. All these flaps survived with a satisfactory patient outcome in most patients.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.