aerodynamic simulation of apds projectile with and without sabot has been conducted here. due to less weight of apds projectile in comparison with the projectile, with the same caliber, apds projectile has higher muzzle velocity, longer range, high penetration capability, and higher impact velocity. simulation of flow around the sabot walls has been carried out in two opening degrees of zero an...

Most mathematical models include parameters that need to be determined from measurements. The estimated values of these parameters and their uncertainties depend on assumptions made about noise levels, models, or prior knowledge. But what can we say about the validity of such estimates, and the influence of these assumptions? This paper is concerned with methods to address these questions, and ...

The purpose of this paper is to analyze the flow field structure in transient state and performance of secondary injection system for thrust vectoring in divergent section of a two-dimensional nozzle. Secondary injection for thrust vectoring in a two-dimensional nozzle is studied by solving three-dimensional Reynolds-averaged equations by means of fluent solver. Spalart-allmaras model was used ...

Abstract An algebraic (zero-equation) transition model is developed to capture multiple mechanisms. The newly devised parameterized using “flow-structure-adaptive” variables and coupled with the truncated Spalart-Allmaras (SA) turbulence model. intermittency factor γ relies on “local flow information” directly linked “vorticity-based production” term of SA Splitting into lower higher regimes “f...

The adjoint approach in gradient-based optimization combined with computational fluid dynamics is commonly applied in various engineering fields. In this work, the gradients are used for the design of a two-dimensional airfoil shape, where the aim is a change in lift and drag coefficient, respectively, to a given target value. The optimizations use the unconstrained quasi-Newton method with an ...

This paper presents a nite element formulation for solving multidimensional compressible ows. This method is inspired by our experience with the SUPG, Finite Volume and Discontinuous-Galerkin methods. Our objective is to obtain a stable and accurate nite element formulation for multidimensional hyperbolic-parabolic problems with particular emphasis on compressible ows. In the proposed formulati...

A computational analysis of an annular converging-diverging (CD) and an altitude adaptive expansion-deflection (ED) nozzle is presented. Numerical results were generated using a 2D axisymmetric, pressure-coupled solver in conjunction with the Spalart-Allmaras turbulence closure model and second order spatial discretisation schemes. Results were recorded over a theoretical altitude range and com...

Reynolds averaged Navier-Stokes methods often cannot predict shock/turbulence interaction correctly. This may be because RANS models do not account for the unsteady motion of the shock wave that is inherent in these interactions. Sinha et al. [Phys. Fluids, Vol. 15, No. 8 (2003)] propose a shock-unsteadiness correction that significantly improves turbulence prediction across a normal shock in a...

The aerodynamic analysis of wind turbine rotors using preconditioned weighted essentially non-oscillatory scheme to solve the compressible NavierStokes equations in non-inertial coordinate system with Spalart-Allmaras one equation turbulence model is presented. A parallel clustering algorithm based on Message Passing Interface library was implemented. The NREL Phase VI rotor with S809 airfoil w...