M. H. Djavareshkian; A. Esmaeili
Volume 10, Issue 2 , September 2013
Abstract
Optimization of the sectional wing in ground effect (WIG) has been studied using ahigh order numerical procedure and response surface method (RSM). Initially, the effects of the ground clearance, angle of attack, thickness, and camber of wing have been investigated by a high-resolutionscheme, which is ...
Read More
Optimization of the sectional wing in ground effect (WIG) has been studied using ahigh order numerical procedure and response surface method (RSM). Initially, the effects of the ground clearance, angle of attack, thickness, and camber of wing have been investigated by a high-resolutionscheme, which is highlystrong and accurate. In the numerical simulation, Normalized Variable Diagram (NVD) scheme is applied to the boundedness criteria. In the optimization process, lift to drag ratio (L/D) is considered as an objective function and static conditions and shape parameters are noticeable to be considered as design variables;.Ths is because the main factor in the design of WIG vehicles is moving near the ground and the distance to the ground draws attention to the significance of it.Therefore, the static conditions strenuously defend this view that they are irrefutable parameters in the aerodynamic optimization of WIG vehicles. Adaptive Neuro-Fuzzy Interface System (ANFIS) is employed to generate the surface response, because the objective function and constraints are particularlynoisy. Sensitivity analysis is also done and the sensitivity amount of the objective function from design variables is explored
mohammad Hassan Djavareshkian; A. Esmaeli; A. Parsania
Volume 7, Issue 2 , September 2010, , Pages 93-106
Abstract
The prediction of aerodynamic characteristics and smart flap of airfoil under the ground effect are carried out by the integration of computational fluid dynamics. Considering different types of beams, a parametric bending profile of a smart flap is designed. Cantilever beam with uniformly varying load ...
Read More
The prediction of aerodynamic characteristics and smart flap of airfoil under the ground effect are carried out by the integration of computational fluid dynamics. Considering different types of beams, a parametric bending profile of a smart flap is designed. Cantilever beam with uniformly varying load with roller support at the free end is considered in here. A pressure-based implicit procedure is utilized to solve Navier-Stokes equations and a nonorthogonal mesh with collocated finite volume formulation is used for simulation. The boundedness criteria for this procedure is determined by Normalized Variable diagram (NVD) scheme. The procedure incorporates the eddy-viscosity turbulence model. The SIMPLE algorithm is applied for turbulent aerodynamic flows around the airfoil with smart and conventional flaps. The results of two flaps are compared for different flap length, flap angle and ground clearance. It is found that: 1- The pressure coefficient distribution in smart flap is smoother than conventional flap. 2- Lift-drag ratio in smart flap is higher than conventional flap. 3- The maximum lift-drag ratio is at flap angle 7.5?. 4- The minimum ground clearance has the highest lift-drag ratio. 5- The increasing of flap length leads to the increasing lift-drag ratio.
