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Beamforming Quantification of Acoustic Transmission Paths for Passenger Vehicles Using a Reciprocal Approach (2023)
Conference Proceeding
Oettle, N., Graham, S., Sims-Williams, D., Riegel, M., & Hebestreit, R. (2023). Beamforming Quantification of Acoustic Transmission Paths for Passenger Vehicles Using a Reciprocal Approach. . https://doi.org/10.4271/2023-01-1090

This paper presents an experimental method for measuring transmission paths from the exterior to the interior of a passenger vehicle using a reciprocal approach: A production vehicle was placed in a semi-anechoic environment; artificial noise sou... Read More about Beamforming Quantification of Acoustic Transmission Paths for Passenger Vehicles Using a Reciprocal Approach.

Flow separation from polygonal cylinders in an incident flow (2023)
Journal Article
Masoudi, E., Sims-Williams, D., & Gan, L. (2023). Flow separation from polygonal cylinders in an incident flow. Physical Review Fluids, 8(1), Article 014701. https://doi.org/10.1103/physrevfluids.8.014701

In this paper, we carry out large eddy simulation of incident flow around polygonal cylinders of side number N = 5 − 8 at Reynolds number Re = 10 4 . In total, six incidence angles ( α ) are studied on each polygon between the face and the corner ori... Read More about Flow separation from polygonal cylinders in an incident flow.

Representative On-Road Aerodynamic Yaw Angle Distribution in China for Vehicle Development (2022)
Journal Article
Xiao, L., Wang, Q., Zhu, X., Bu, H., Huang, T., Yuan, X., …Sims-Williams, D. B. (2022). Representative On-Road Aerodynamic Yaw Angle Distribution in China for Vehicle Development. SAE International Journal of Passenger Vehicle Systems, 16(2), https://doi.org/10.4271/15-16-02-0008

Aerodynamic drag for road vehicles is most often assessed based on zero yaw conditions. The rise of electric vehicles in recent years put greater demand on how the vehicles perform in real-world conditions. Specifically, the aerodynamic drag performa... Read More about Representative On-Road Aerodynamic Yaw Angle Distribution in China for Vehicle Development.

Large Eddy Simulation of incident flows around polygonal cylinders (2021)
Journal Article
Masoudi, E., Gan, L., & Sims-Williams, D. (2021). Large Eddy Simulation of incident flows around polygonal cylinders. Physics of Fluids, 33(10), Article 105112. https://doi.org/10.1063/5.0063046

In this study, we carry out large eddy simulation (LES) of incident flow around polygonal cylinders of side number N = 5 − 8 at Reynolds number Re= 104 . In total, six incidence angles (α) are studied on each cylinder ranging from face to corner orie... Read More about Large Eddy Simulation of incident flows around polygonal cylinders.

Near wake flow features of polygonal cylinders in different incidence angles (2021)
Presentation / Conference
Masoudi, E., Gan, L., & Sims-Williams, D. (2021, September). Near wake flow features of polygonal cylinders in different incidence angles. Paper presented at UK Fluids Conference 2021, Online

In this study, large eddy simulation (LES) is used to simulate flow of incidence angle α around polygonal cylinders of side number N=5-8 at Reynolds number Re=10,000. Six incidence angles are studied on each cylinder, which covers the entire α spect... Read More about Near wake flow features of polygonal cylinders in different incidence angles.

Automotive aeroacoustics: An overview (2017)
Journal Article
Oettle, N., & Sims-Williams, D. (2017). Automotive aeroacoustics: An overview. Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering, 231(9), 1177-1189. https://doi.org/10.1177/0954407017695147

Vehicle aeroacoustic performance has a major influence on customer perception and also has importance for safety and comfort. Wind noise performance was once differentiated by the quality of sealing. Today, achieving competitive wind noise performanc... Read More about Automotive aeroacoustics: An overview.

Aerodynamic Analysis of Grand Prix Cars Operating in Wake Flows (2017)
Journal Article
Newbon, J., Sims-Williams, D., & Dominy, R. (2017). Aerodynamic Analysis of Grand Prix Cars Operating in Wake Flows. SAE International Journal of Passenger Cars - Mechanical Systems, 10(1), 318-329. https://doi.org/10.4271/2017-01-1546

The effect of the upstream wake of a Formula 1 car on a following vehicle has been investigated using experimental and computational methods. Multiple vehicle studies in conventional length wind tunnels pose challenges in achieving a realistic vehicl... Read More about Aerodynamic Analysis of Grand Prix Cars Operating in Wake Flows.

Analysis of the Impacts of Formula 1 Car Wakes on the Aerodynamic Performance of a Following Vehicle (2016)
Conference Proceeding
Newbon, J., Sims-Williams, D., & Dominy, R. (2016). Analysis of the Impacts of Formula 1 Car Wakes on the Aerodynamic Performance of a Following Vehicle.

This paper investigates the impact of the wake of a Formula 1 geometry on a following vehicle. For the case considered, the vehicle downforce is seen to be reacted by the pressure force on the ground plane, resulting in little net up-wash in the wake... Read More about Analysis of the Impacts of Formula 1 Car Wakes on the Aerodynamic Performance of a Following Vehicle.

Investigations of the Rear-End Flow Structures on a Sedan Car (2016)
Conference Proceeding
Kounenis, C., Bonitz, S., Ljungskog, E., Sims-Williams, D., Lofdahl, L., Broniewicz, A., …Sebben, S. (2016). Investigations of the Rear-End Flow Structures on a Sedan Car. . https://doi.org/10.4271/2016-01-1606

The aerodynamic drag, fuel consumption and hence CO2 emissions, of a road vehicle depend strongly on its flow structures and the pressure drag generated. The rear end flow which is an area of complex three-dimensional flow structures, contributes to... Read More about Investigations of the Rear-End Flow Structures on a Sedan Car.

CFD Investigation of the Effect of the Salient Flow Features in the Wake of a Generic Open-Wheel Race Car (2015)
Journal Article
Newbon, J., Dominy, R., & Sims-Williams, D. (2015). CFD Investigation of the Effect of the Salient Flow Features in the Wake of a Generic Open-Wheel Race Car. SAE International Journal of Passenger Cars - Mechanical Systems, 8(1), 217-232. https://doi.org/10.4271/2015-01-1539

It is well known that in motorsport the wake from an upstream vehicle can be detrimental to the handling characteristics of a following vehicle, in particular in formulae with high levels of downforce. Previous investigations have been performed to c... Read More about CFD Investigation of the Effect of the Salient Flow Features in the Wake of a Generic Open-Wheel Race Car.

The Effects of Unsteady Flow Conditions on Vehicle in Cabin and External Noise Generation (2015)
Conference Proceeding
Kounenis, C., Sims-Williams, D., Dominy, R., Berson, A., Oettle, N., & Freeman, C. (2015). The Effects of Unsteady Flow Conditions on Vehicle in Cabin and External Noise Generation. . https://doi.org/10.4271/2015-01-1555

A vehicle driving on the road experiences unsteady flow conditions which are not generally reproduced in the development environment. This paper investigates the potential importance of this difference to aeroacoustics and hence to occupant perceptio... Read More about The Effects of Unsteady Flow Conditions on Vehicle in Cabin and External Noise Generation.

Investigation into the effect of the wake from a generic formula one car on a downstream vehicle (2014)
Conference Proceeding
Newbon, J., Sims-Williams, D., & Dominy, R. (2014). Investigation into the effect of the wake from a generic formula one car on a downstream vehicle. In International vehicle aerodynamics conference : Holywell Park, Loughborough, UK 14-15 October 2014 (213-223)

The aerodynamic performance of an open wheel race car is significantly affected when following another vehicle. This paper presents experimental and CFD results for a generic 25% scale Formula one car operating in the wake of another vehicle. Differe... Read More about Investigation into the effect of the wake from a generic formula one car on a downstream vehicle.

Interactions between Underbody Aerodynamics and Aeroacoustics (2014)
Conference Proceeding
Kounenis, C., Sims-Williams, D., Dominy, R., Berson, A., & Oettle, N. (2014). Interactions between Underbody Aerodynamics and Aeroacoustics. In International vehicle aerodynamics conference : Holywell Park, Loughborough, UK 14-15 October 2014 (263-273)

Research has shown that lack of ground effect simulation in the wind tunnel could result in different flow conditions from those experienced by the vehicle on the road, influencing aerodynamic noise inside the cabin. The focus of this work is the inf... Read More about Interactions between Underbody Aerodynamics and Aeroacoustics.

A Wind Tunnel Simulation Facility for On-Road Transients (2014)
Journal Article
Mankowski, O., Sims-Williams, D., & Dominy, R. (2014). A Wind Tunnel Simulation Facility for On-Road Transients. SAE International Journal of Passenger Cars - Mechanical Systems, 7(3), 1087-1095. https://doi.org/10.4271/2014-01-0587

This paper outlines the creation of a facility for simulating on-road transients in a model scale, ¾ open jet, wind tunnel. Aerodynamic transients experienced on-road can be important in relation to a number of attributes including vehicle handling a... Read More about A Wind Tunnel Simulation Facility for On-Road Transients.

Assessing the Aeroacoustic Response of a Vehicle to Transient Flow Conditions from the Perspective of a Vehicle Occupant (2014)
Journal Article
Oettle, N., Sims-Williams, D., & Dominy, R. (2014). Assessing the Aeroacoustic Response of a Vehicle to Transient Flow Conditions from the Perspective of a Vehicle Occupant. SAE International Journal of Passenger Cars - Mechanical Systems, 7(2), 550-558. https://doi.org/10.4271/2014-01-0591

On-road, a vehicle experiences unsteady flow conditions due to turbulence in the natural wind, moving through the unsteady wakes of other road vehicles and travelling through the stationary wakes generated by roadside obstacles. Separated flow struct... Read More about Assessing the Aeroacoustic Response of a Vehicle to Transient Flow Conditions from the Perspective of a Vehicle Occupant.

An Active Turbulence Generation System for the Simulation of Aerodynamic Transients in a Model Wind Tunnel (2014)
Conference Proceeding
Mankowski, O., Sims-Williams, D., Hunt, A., & Dominy, R. (2014). An Active Turbulence Generation System for the Simulation of Aerodynamic Transients in a Model Wind Tunnel.

This paper outlines the creation and validation of an active turbulence generation system (TGS) for the simulation of wind and vehicle-induced transients in a model scale, ¾ open jet, wind tunnel.

Evaluation of the Aerodynamic and Aeroacoustic Response of a Vehicle to Transient Flow Conditions (2013)
Journal Article
Oettle, N., Mankowski, O., Sims-Williams, D., Dominy, R., & Freeman, C. (2013). Evaluation of the Aerodynamic and Aeroacoustic Response of a Vehicle to Transient Flow Conditions. SAE International Journal of Passenger Cars - Mechanical Systems, 6(1), 389-402. https://doi.org/10.4271/2013-01-1250

A vehicle on the road encounters an unsteady flow due to turbulence in the natural wind, unsteady wakes of other vehicles and as a result of traversing through the stationary wakes of roadside obstacles. Unsteady effects occurring in the sideglass re... Read More about Evaluation of the Aerodynamic and Aeroacoustic Response of a Vehicle to Transient Flow Conditions.

The Aerodynamic Characteristics of a Fully Deformable Formula One Wind Tunnel Tyre (2012)
Journal Article
Sprot, A., Sims-Williams, D., & Dominy, R. (2012). The Aerodynamic Characteristics of a Fully Deformable Formula One Wind Tunnel Tyre. SAE International Journal of Passenger Cars - Mechanical Systems, 5(2), 1026-1041. https://doi.org/10.4271/2012-01-1166

Competitive aerodynamic performance of a Formula One car relies upon total understanding of the downstream wake of exposed rotating wheels. Sensitivities to the downstream vortices and low stagnation-pressure regions lead to subtle design decisions i... Read More about The Aerodynamic Characteristics of a Fully Deformable Formula One Wind Tunnel Tyre.

Bluff Body Drag Reduction with Ventilated Base Cavities (2012)
Journal Article
Howell, J., Sims-Williams, D., Sprot, A., Hamlin, F., & Dominy, R. (2012). Bluff Body Drag Reduction with Ventilated Base Cavities. SAE International Journal of Passenger Cars - Mechanical Systems, 5(1), 152-160. https://doi.org/10.4271/2012-01-0171

Various techniques to reduce the aerodynamic drag of bluff bodies through the mechanism of base pressure recovery have been investigated. These include, for example, boat-tailing, base cavities and base bleed. In this study an Ahmed body in squarebac... Read More about Bluff Body Drag Reduction with Ventilated Base Cavities.

Reconstruction of the Unsteady Pressure Field in a Low Speed Linear Cascade (2012)
Conference Proceeding
Förster, F., Sims-Williams, D., & Ingram, G. (2012). Reconstruction of the Unsteady Pressure Field in a Low Speed Linear Cascade. In ASME Turbo Expo 2012 : turbine technical conference and exposition (2653-2662). https://doi.org/10.1115/gt2012-69156

This paper describes investigations into unsteady flow phenomena in a high turning linear cascade with a nominal steady flow. A fast response five hole probe was used to obtain time-accurate measurements. Since a single probe was used to traverse an... Read More about Reconstruction of the Unsteady Pressure Field in a Low Speed Linear Cascade.

The Bandwidth of Transient Yaw Effects on Vehicle Aerodynamics (2011)
Journal Article
Mankowski, O., Sims-Williams, D., Dominy, R., Duncan, B., & Gargoloff, J. (2011). The Bandwidth of Transient Yaw Effects on Vehicle Aerodynamics. SAE International Journal of Passenger Cars - Mechanical Systems, 4(1), 131-142. https://doi.org/10.4271/2011-01-0160

A vehicle on the road encounters an unsteady flow due to turbulence in the natural wind, the unsteady wakes from other vehicles and as a result of traversing through the stationary wakes of road side obstacles. There is increasing concern about poten... Read More about The Bandwidth of Transient Yaw Effects on Vehicle Aerodynamics.

Cross Winds and Transients: Reality, Simulation and Effects (2011)
Journal Article
Sims-Williams, D. (2011). Cross Winds and Transients: Reality, Simulation and Effects. SAE International Journal of Passenger Cars - Mechanical Systems, 4(1), 172-183. https://doi.org/10.4271/2011-01-0172

This paper provides a published counterpart to the address of the same title at the 2010 SAE World Congress. A vehicle on the road encounters an unsteady flow due to turbulence in the natural wind, due to the unsteady wakes of other vehicles and as a... Read More about Cross Winds and Transients: Reality, Simulation and Effects.

Aerodynamic Investigation on the Effect of Varying Through-Hub Flow on a Formula One Front Wheel Assembly (2011)
Journal Article
Sprot, A., Minto, J., Sims-Williams, D., & Dominy, R. (2011). Aerodynamic Investigation on the Effect of Varying Through-Hub Flow on a Formula One Front Wheel Assembly. SAE International Journal of Passenger Cars - Mechanical Systems, 4(1), 929-944. https://doi.org/10.4271/2011-01-1431

For open wheel race cars the front wheel flow and the interaction of its wake with downstream components is of significant importance. Considerable effort goes into the design of front wing end plates, barge boards and underfloor components in order... Read More about Aerodynamic Investigation on the Effect of Varying Through-Hub Flow on a Formula One Front Wheel Assembly.

Links between Notchback Geometry, Aerodynamic Drag, Flow Asymmetry and Unsteady Wake Structure (2011)
Journal Article
Sims-Williams, D., Marwood, D., & Sprot, A. (2011). Links between Notchback Geometry, Aerodynamic Drag, Flow Asymmetry and Unsteady Wake Structure. SAE International Journal of Passenger Cars - Mechanical Systems, 4(1), 156-165. https://doi.org/10.4271/2011-01-0166

The rear end geometry of road vehicles has a significant impact on aerodynamic drag and hence on energy consumption. Notchback (sedan) geometries can produce a particularly complex flow structure which can include substantial flow asymmetry. However,... Read More about Links between Notchback Geometry, Aerodynamic Drag, Flow Asymmetry and Unsteady Wake Structure.

The Effects of Unsteady On-Road Flow Conditions on Cabin Noise: Spectral and Geometric Dependence (2011)
Journal Article
Oettle, N., Sims-Williams, D., Dominy, R., Darlington, C., & Freeman, C. (2011). The Effects of Unsteady On-Road Flow Conditions on Cabin Noise: Spectral and Geometric Dependence. SAE International Journal of Passenger Cars - Mechanical Systems, 4(1), 120-130. https://doi.org/10.4271/2011-01-0159

The in-cabin sound pressure level response of a vehicle in yawed wind conditions can differ significantly between the smooth flow conditions of the aeroacoustic wind tunnel and the higher turbulence, transient flow conditions experienced on the road.... Read More about The Effects of Unsteady On-Road Flow Conditions on Cabin Noise: Spectral and Geometric Dependence.

Time resolved measurements in the Durham Cascade (2011)
Conference Proceeding
Forster, F., Sims-Williams, D., Ingram, G., & Dominy, R. (2011). Time resolved measurements in the Durham Cascade. . https://doi.org/10.1115/gt2011-45838

This paper describes investigations into unsteady flow phenomena in a high turning linear cascade with a nominal steady flow. Traditionally time averaged instrumentation is used in such a cascade. Detailed intermittency readings were taken inside the... Read More about Time resolved measurements in the Durham Cascade.

The Effects of Unsteady On-Road Flow Conditions on Cabin Noise. (2010)
Conference Proceeding
Oettle, N., Sims-Williams, D., Dominy, R., Darlington, C., Freeman, C., & Tindall, P. (2010). The Effects of Unsteady On-Road Flow Conditions on Cabin Noise. . https://doi.org/10.4271/2010-01-0289

At higher speeds aerodynamic noise tends to dominate the overall noise inside the passenger compartment. Large-scale turbulent conditions experienced on the road can generate different noise characteristics from those under steady-state conditions ex... Read More about The Effects of Unsteady On-Road Flow Conditions on Cabin Noise..

Fabrication of an in-plane SU-8 cantilever with integrated strain gauge for wall shear stress measurements in fluid flows (2009)
Conference Proceeding
Allen, N., Wood, D., Rosamond, M., & Sims-Williams, D. (2009). Fabrication of an in-plane SU-8 cantilever with integrated strain gauge for wall shear stress measurements in fluid flows. In J. Brugger, & D. Briand (Eds.), Proceedings of the Eurosensors XXIII conference (923-926). https://doi.org/10.1016/j.proche.2009.07.230

We present a cantilever fabricated from the polymer SU-8 for the measurement of wall shear stress in fluid flows. The pressure induced deflection of the cantilever, measured using a calibrated and integrated nichrome strain gauge, can be related to t... Read More about Fabrication of an in-plane SU-8 cantilever with integrated strain gauge for wall shear stress measurements in fluid flows.

Effects of On-Road Turbulence on Vehicle Surface Pressures in the A-Pillar Region. (2008)
Journal Article
Lawson, A., Sims-Williams, D., & Dominy, R. (2008). Effects of On-Road Turbulence on Vehicle Surface Pressures in the A-Pillar Region. SAE International Journal of Passenger Cars - Mechanical Systems, 1(1), 333-340. https://doi.org/10.4271/2008-01-0474

There is increasing concern about potential differences in aerodynamic behavior measured in steady flow wind tunnel conditions and that which occurs for vehicles on the road. As tools become available for better simulation of on road conditions there... Read More about Effects of On-Road Turbulence on Vehicle Surface Pressures in the A-Pillar Region..

Unsteady Measurement with Correction on Tubing Distortion (2006)
Book Chapter
Yang, H., Sims-Williams, D., & He, L. (2006). Unsteady Measurement with Correction on Tubing Distortion. In K. Hall, R. Kielb, & J. Thomas (Eds.), Unsteady Aerodynamics, Aeroacoustics and Aeroelasticity of Turbomachines. Springer Verlag

The aerodynamic stability of a Le Mans prototype race car under off-design pitch conditions (2000)
Journal Article
Dominy, R., Ryan, A., & Sims-Williams, D. (2000). The aerodynamic stability of a Le Mans prototype race car under off-design pitch conditions. SAE transactions, 109(6), 1454-1460. https://doi.org/10.4271/2000-01-0872

The current generation of sports racing cars such as those competing under the Le Mans “LM”P and “LM”GTP regulations are particularly sensitive to the pitch of the vehicle. This is a consequence of the low ground clearances that must be adopted to ma... Read More about The aerodynamic stability of a Le Mans prototype race car under off-design pitch conditions.