The optimal placement of sensors for the estimation of turbulence model parameters in computational fluid dynamics is presented. The information entropy (IE), applied on the posterior uncertainty of the model parameters inferred from Bayesian analysis, is used as a scalar measure of uncertainty. Using an asymptotic approximation, the IE depends on nominal values of the CFD model and prediction ...

Abstract The blended-wing body is an aircraft configuration that has the potential to be more efficient than conventional large transport aircraft configurations with the same capability. However, the design of the blended-wing is challenging due to the tight coupling between aerodynamic performance, trim, and stability. Other design challenges include the nature and number of the design variab...

This paper presents an original approach regarding the application of sweep to rotating blade cascades. The justification for swept blades is given by its consequence, i.e. a reduction of local velocity (usually from supersonic/ transonic to subsonic regimes) such that the losses due to shock waves and/or boundary layer displacement and/or followed by reattachment are minimized. As study cases ...

The effect of ambient turbulence intensity on the flow induced oscillations rigid circular cylinders with symmetric and asymmetric local stimulation is studied. Cylinders oscillate in one degree freedom transversely to a steady uniform flow. Two-dimensional unsteady Reynolds-Average Navier-Stokes equations Spalart-Allmaras model are used solve problem numerically. Three freestream values (0.2%,...

Abstract This paper compares the performance of four low-Reynolds-number models for the unsteady Reynolds-averaged Navier-Stokes equations applied to the flow in a channel driven by a pressure gradient oscillating around a non-zero mean. The models considered are the one-equation Spalart-Allmaras model, the k − ε model with the wall functions of Lam and Bremhorst, the k−ω model of Saffman and W...

An assessment of unstructured grids for use in Detached-Eddy Simulation (and more generally in Large-Eddy Simulation) of massively separated ows is presented. The role of the grid, its generation and re nement, are considered via calculation of three high-Reynolds number turbulent ows of aerodynamic interest: the massively separated ow over a forebody in cross ow, the ow over a delta wing at 27...

An adjoint-based Navier–Stokes design and optimization method for two-dimensional multi-element high-lift configurations is derived and presented. The compressible Reynolds-averaged Navier–Stokes equations are used as a flow model together with the Spalart–Allmaras turbulence model to account for high Reynolds number effects. When a viscous continuous adjoint formulation is used, the necessary ...

We present a practical approach for the numerical solution of the Reynolds averaged Navier-Stokes (RANS) equations using high-order discontinuous Galerkin methods. Turbulence is modeled by the Spalart-Allmaras (SA) one-equation model. We introduce an artificial viscosity model for SA equation which is aimed at accommodating high-order RANS approximations on grids which would otherwise be too co...

The air layer formation in a high Reynolds-number flat plate turbulent boundary layer is simulated using a two-phase sharp interface Cartesian grid solver. The interface is tracked by a coupled level set and volume-of-fluid method (CLSVOF) and turbulence is modeled by a Spalart-Allmaras (SA) turbulence model with a wall function (WF) approach. The air layer along the entire test plate is succes...

Numerical investigation was performed on NACA 0015 which is a symmetric airfoil. Pressure distribution and then lift and drag forces are verified. Changing of ground clearance was a considerable point. Also the angle of attack was changed from 0° to 10°. Pressure coefficient reaches its higher amounts on the wing lower surface when the ground clearance diminishes. Increment of the angle of atta...