Investigation of Aerodynamic Drag in Turbulent Flow Conditions

Stoll, Daniel; Schoenleber, Christoph; Wittmeier, Felix; Kuthada, Timo; Wiedemann, Jochen

doi:10.4271/2016-01-1605

Cited by 34 publications

(24 citation statements)

References 23 publications

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“…Figure10. Comparisons of changes in fluid-dynamic coefficients depending on normalized yaw rate ω' between present measurement at Re = (6.45 ± 0.06) × 10 5 and previous numerical analysis result by Keogh et al[13] at Re = 1.70 × 10 6 : (a) change in drag coefficient ΔCD; (b) change in lift coefficient ΔCL.…”

supporting

confidence: 49%

“…However, the impact of more realistic on-road disturbances on automobile aerodynamics has attracted attention to further increase the accuracy when evaluating the aerodynamic performance of an automobile on a road. For example, the on-road turbulence properties [6,7] and the effects of their fluctuation on the aerodynamic drag [8][9][10] have been investigated. The changes in the aerodynamic drag due to more specific disturbances from a passing vehicle [11] have also been reported.…”

Section: Introductionmentioning

confidence: 99%

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Fluid-Dynamic Force Measurement of Ahmed Model in Steady-State Cornering

et al. 2020

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The effects of on-road disturbances on the aerodynamic drag are attracting attention in order to accurately evaluate the fuel efficiency of an automobile on a road. The present study investigated the effects of cornering motion on automobile aerodynamics, especially focusing on the aerodynamic drag. Using a towing tank facility, measurements of the fluid-dynamic force acting on Ahmed models during steady-state cornering were conducted in water. The investigation included Ahmed models with slant angles θ = 25° and 35°, reproducing the wake structures of two different types of automobiles. The drag increase due to steady-state cornering motion was experimentally measured, and showed good agreement with previous numerical research, with the measurements conducted at a Reynolds number of 6 × 105, based on the model length. The Ahmed model with θ = 35° showed a greater drag increase due to the steady-state cornering motion than that with θ = 25°, and it reached 15% of the total drag at a corner with a radius that was 10 times the vehicle length. The results indicated that the effect of the cornering motion on the automobile aerodynamics would be more important, depending on the type of automobile and its wake characteristics.

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supporting

confidence: 49%

Section: Introductionmentioning

confidence: 99%

Fluid-Dynamic Force Measurement of Ahmed Model in Steady-State Cornering

et al. 2020

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“…The literature mainly focusses on drag reduction at zero degree yaw and with low turbulence onset flows, which neglects a number of potentially significant on-road effects [16][17][18][19]. However, Englar et al [11] and Englar [12] present work on streamlined bodies as well as heavy goods vehicles at a large range of yaw angles using jets of air at various locations close to, or around, the rear of the geometry to control all of the force and moment coefficients.…”

Section: Introductionmentioning

confidence: 99%

Parametric Study of Asymmetric Side Tapering in Constant Cross Wind Conditions

Varney¹,

Passmore²,

Gaylard³

2018

SAE Int. J. Passeng. Cars - Mech. Syst.

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Sports Utility Vehicles (SUVs) often have blunt rear end geometries for design and practicality, which is not typically aerodynamic. Drag can be reduced with a number of passive and active methods, which are generally prioritised at zero yaw, which is not entirely representative of the "on road" environment. As such, to combine a visually square geometry (at rest) with optimal drag reductions at non-zero yaw, an adaptive system that applies vertical side edge tapers independently is tested statically. A parametric study has been undertaken in Loughborough University's Large Wind Tunnel with the ¼ scale Windsor Model. The aerodynamic effect of implementing asymmetric side tapering has been assessed for a range of yaw angles (∘ , ±. ∘ , ± ∘ and ± ∘) on the force and moment coefficients. This adaptive system reduced drag at every non-zero yaw angle tested, from the simplest geometry (full body taper without wheels) to the most complex geometry (upper body taper with wheels) with varying levels of success; providing additional drag reductions from 3% to 125%. The system also shows potential to beneficially modify the cross wind stability of the geometry.

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“…To give the travelers in an auto with an agreeable lodge, the car air conditioning (A/C) unit should deal with obnoxious impacts of temperature, humidity, and air flow and heat radiation. To perform this undertaking, the A/C unit needs to cool and heat air, dehumidify and allow the air to flow legitimately in various parts of the vehicle cabin, by controlling through four individual parts; an air flow mode selector, a blower, cooler and heater (Stoll et al 2016). Most vehicles utilize a ventilating framework to enhance thermal solace in the compartment.…”

Section: Literature Surveymentioning

confidence: 99%

An Investigation of Air Flow and Thermal Comfort of Modified Conventional Car Cabin Using Computerized Fluid Dynamics

2018

JAFM

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Air conditioning is widely used in many areas to reduce the heat and humidity of the work place and to maintain a room temperature for thermal stability and physical ability to perform various tasks. Computational Fluid Dynamics (CFD) is based on the numerical solutions of the fundamental governing equations of fluid dynamics namely the continuity, momentum and energy equations. Computerized fluent mechanics is one of the increasing paradigm in the air flow simulation in vehicle designs. The design optimization of vehicle can offer better efficiency in cabin surface as well as aerodynamic. In vehicles, air conditioning tends to offer efficient thermal conditioning and air circulation inside the cabin for passenger comfort from different climate variation. Almost all the automobiles available in the market are fitted with airconditioning systems. The manufacturers focus clearly on the AC system for a wide variety of climates. As technology advances, AC system is also adhering major advancements. In general, automobile airconditioning systems are designed to provide comfort for the driver and the passengers during a journey. The conventional electrical-driven compression systems are widely used in almost all of the automobiles today. An air-conditioner is operated to make a hot and humid passenger compartment a more comfortable environment. However, with the improvement in vehicle fuel economy, the allowable power consumption for the air-conditioner has been decreasing, in relation to the overall power consumption of the vehicle. The internal temperature-humidity conditions are an essential factor for the comfort and health of passengers, and also for the safety of drivers. In this research, the air conditioning inside vehicle cabin is analyzed. The objective of the research is to develop an air depression design inside the top surfaces of the rear cabin. The optimal flow of air inside cabin increases the thermal comfort of the vehicle. The proposed cabin depression design inside the rear top surfaces are analyzed under thermal variation and airflow circulation inside the cabin. The Ansys fluent tool is utilized in this paper to evaluate the variation of air flow and the temperature inside the passenger vehicle cabin respectively. From the research analysis, the proposed evaluation of the depression design is more optimal for air conditioning in budgetary small passenger vehicles.

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Investigation of Aerodynamic Drag in Turbulent Flow Conditions

Cited by 34 publications

References 23 publications

Fluid-Dynamic Force Measurement of Ahmed Model in Steady-State Cornering

Fluid-Dynamic Force Measurement of Ahmed Model in Steady-State Cornering

Parametric Study of Asymmetric Side Tapering in Constant Cross Wind Conditions

An Investigation of Air Flow and Thermal Comfort of Modified Conventional Car Cabin Using Computerized Fluid Dynamics

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