Models for the study of computational fluid dynamics in vehicles to determine aerodynamic loads usually take into account only the geometry of the body. Several constructive elements such as the wheel geometry or susp...Models for the study of computational fluid dynamics in vehicles to determine aerodynamic loads usually take into account only the geometry of the body. Several constructive elements such as the wheel geometry or suspension components are disregarded in the computational models. This work presents the study of the aerodynamics of a one-fourth model passenger vehicle, which contains the wheelhouse interior elements. The goal is to identify the aerodynamic loads produced by these components and their effect on the flow dynamics. Wheel and tire set, brake components, suspension and drive shaft are contemplated. Computer simulations were performed to the vehicle speed varying from 0 to 120 km/h and included the rotation of the tire and wheel assembly, considering the tire geometry in dynamic conditions. The computational model is solved by the finite volume method, wherein the computational domain is divided into tetrahedral and hexahedral elements. The turbulence model used is the standard k −ε.展开更多
Aerodynamic drag is a large resistance force to vehicle motion,particularly at highway speeds.Conventional wheel deflectors were designed to reduce the wheel drag and,consequently,the overall vehicle drag;however,they...Aerodynamic drag is a large resistance force to vehicle motion,particularly at highway speeds.Conventional wheel deflectors were designed to reduce the wheel drag and,consequently,the overall vehicle drag;however,they may actually be detrimental to vehicle aerodynamics in modern designs.In the present study,computational fluid dynamics simulations were conducted on the notchback DrivAer model-a simplified,yet realistic,open-source vehicle model that incorporates features of a modern passenger vehicle.Conventional and air-jet wheel deflectors upstream of the front wheels were introduced to assess the effect of underbody-flow deflection on the vehicle drag.Conventional wheel-deflector designs with varying heights were observed and compared to 45◦and 90◦air-jet wheel deflectors.The conventional wheel deflectors reduced wheel drag but resulted in an overall drag increase of up to 10%.For the cases studied,the 90◦air jet did not reduce the overall drag compared to the baseline case;the 45◦air jet presented drag benefits of up to 1.5%at 35 m/s and above.Compared to conventional wheel deflectors,air-jet wheel deflectors have the potential to reduce vehicle drag to a greater extent and present the benefit of being turned off at lower speeds when flow deflection is undesirable,thus improving efficiency and reducing emissions.展开更多
文摘Models for the study of computational fluid dynamics in vehicles to determine aerodynamic loads usually take into account only the geometry of the body. Several constructive elements such as the wheel geometry or suspension components are disregarded in the computational models. This work presents the study of the aerodynamics of a one-fourth model passenger vehicle, which contains the wheelhouse interior elements. The goal is to identify the aerodynamic loads produced by these components and their effect on the flow dynamics. Wheel and tire set, brake components, suspension and drive shaft are contemplated. Computer simulations were performed to the vehicle speed varying from 0 to 120 km/h and included the rotation of the tire and wheel assembly, considering the tire geometry in dynamic conditions. The computational model is solved by the finite volume method, wherein the computational domain is divided into tetrahedral and hexahedral elements. The turbulence model used is the standard k −ε.
文摘Aerodynamic drag is a large resistance force to vehicle motion,particularly at highway speeds.Conventional wheel deflectors were designed to reduce the wheel drag and,consequently,the overall vehicle drag;however,they may actually be detrimental to vehicle aerodynamics in modern designs.In the present study,computational fluid dynamics simulations were conducted on the notchback DrivAer model-a simplified,yet realistic,open-source vehicle model that incorporates features of a modern passenger vehicle.Conventional and air-jet wheel deflectors upstream of the front wheels were introduced to assess the effect of underbody-flow deflection on the vehicle drag.Conventional wheel-deflector designs with varying heights were observed and compared to 45◦and 90◦air-jet wheel deflectors.The conventional wheel deflectors reduced wheel drag but resulted in an overall drag increase of up to 10%.For the cases studied,the 90◦air jet did not reduce the overall drag compared to the baseline case;the 45◦air jet presented drag benefits of up to 1.5%at 35 m/s and above.Compared to conventional wheel deflectors,air-jet wheel deflectors have the potential to reduce vehicle drag to a greater extent and present the benefit of being turned off at lower speeds when flow deflection is undesirable,thus improving efficiency and reducing emissions.
