Browse Topic: Drag
The Mahindra XUV 3XO is a compact SUV, the first-generation of which was introduced in 2018. This paper explores some of the challenges entailed in developing the subsequent generation of this successful product, maintaining exterior design cues while at the same time improving its aerodynamic efficiency. A development approach is outlined that made use of both CFD simulation and Coastdown testing at MSPT (Mahindra SUV proving track). Drag coefficient improvement of 40 counts (1 count = 0.001 Cd) can be obtained for the best vehicle exterior configuration by paying particular attention to: AGS development to limit the drag due to cooling airflow into the engine compartment Front wheel deflector optimization Mid underbody cover development (beside the LH & RH side skirting) Wheel Rim optimization In this paper we have analyzed the impact of these design changes on the aerodynamic flow field, Pressure plots and consequently drag development over the vehicle length is highlighted. An
Reducing drag forces and minimizing the rear wake region are the main goals of evaluating exterior aerodynamic performance in automobiles. Various literature and experiments shows that the overall fuel computations of the road vehicle improves significantly with the reduction in aerodynamic drag force. In the road vehicle major components of the drag is due the imbalance in pressure between front and rear of the vehicle. At high vehicle speed, aerodynamic drag is responsible for approximately 30 to 40% of the energy consumption of the vehicle. In the recent year, cost of high-performance computing (HPC) has reduced significantly, which helped computational fluid dynamics (CFD) is an affordable tool to the automotive industry for evaluating aerodynamic performance of the vehicle during developing phase. The vehicles aerodynamic performance is greatly impacted by the dynamic environmental conditions it encounters in the real world. Such environmental conditions are difficult to replicate
The front wing is a critical component of a Formula 1 car, directly influencing aerodynamic efficiency and overall performance. This study focuses on optimizing the computational simulation process for a Formula 1 front wing, using the Imperial Front Wing (IFW) model as a benchmark. Computational Fluid Dynamics (CFD) simulations were for this study, with a particular emphasis on evaluating ground effect and aerodynamic drag characteristics. A higher ground height configuration of the IFW is evaluated in this study. The results, including aerodynamic coefficients and fluid flow visualizations, were compared with findings from previous literature to assess their accuracy and consistency. The study demonstrated strong alignment with theoretical expectations, validating the simulation approach. Additionally, this research lays the groundwork for further refinements in mesh optimization and simulation methodologies, contributing to more efficient aerodynamic analysis in high-performance
As automotive manufacturers have tried to set themselves apart by reducing emissions, and increasing vehicle range/fuel economy by eliminating any energy loss from inefficiencies on the vehicle, the brake corners have been an area of interest to reduce off-brake torque to zero in all conditions. Caliper designers can revise some attributes like piston seal grooves, and pad retraction features to reduce drag, but even if a caliper is designed perfectly in all aspects, trying to measure it in a reliable and repeatable manner proves to be difficult. There are many ways to measure brake drag all with ranging complexity. Some of the simplest measurements are the most repeatable, but it excludes the majority of the vehicle inputs. The most vehicle representative testing requires the most complex equipment and comes with the most challenges. This paper will focus mainly on the different ways residual brake drag can be measured, the benefits and challenges to each of them, the problems trying
Experimental studies of wind tunnel blockage for road vehicles have usually been conducted in model wind tunnels. Models have been made in a range of scales and tested in a working section of fixed size. More recently CFD studies of blockage have been undertaken, which allow a fixed vehicle size and the blockage is varied by changing the cross section of the flow domain. This has some inherent advantages. A very recent database of CFD derived drag and lift coefficients for different road vehicle shapes and simple bodies tested in a closed wall tunnel with a wide range of blockage ratios has become available and provides some additional insight into the blockage phenomenon. In this paper a process is developed to derive the parameters influencing wind tunnel blockage corrections from CFD data. These are shown to be reasonably effective for correcting the measured drag and lift coefficients at blockage ratios up to 10%.
The current Range Rover is the fifth generation of this luxury SUV. With a drag coefficient of 0.30 at launch, it was the most aerodynamically efficient luxury SUV in the world. This aerodynamic efficiency was achieved by applying the latest science. Rear wake control was realised with a large roof spoiler, rear pillar and bodyside shaping, along with an under-floor designed to reduce losses over a wide range of vehicle configurations. This enabled manipulation of the wake structure to reduce drag spread, optimising emissions measured under the WLTP regulations. Along with its low drag coefficient, in an industry first, it was developed explicitly to achieve reduced rear surface contamination with reductions achieved of 70% on the rear screen and 60% over the tailgate when compared against the outgoing product. This supports both perceptions of luxury along with sensor system performance, demonstrating that vehicles can be developed concurrently for low drag and reduced rear soiling
Vehicle handling is significantly influenced by aerodynamic forces, which alter the normal load distribution across all four wheels, affecting vehicle stability. These forces, including lift, drag, and side forces, cause complex weight transfers and vary non-linearly with vehicle apparent velocity and orientation relative to wind direction. In this study, we simulate the vehicle traveling on a circular path with constant steering input, calculate the normal load on each tire using a weight transfer formula, calculate the effect of lift force on the vehicle on the front and rear, and calculate the vehicle dynamic relation at steady state because the frequency of change due to aerodynamic load is significantly less than that of the yaw rate response. The wind velocity vector is constant while the vehicle drives in a circle, so the apparent wind velocity relative to the car is cyclical. Our approach focuses on the interaction between two fundamental non-linearity’s: the nonlinear
Items per page:
50
1 – 50 of 4467