Upstream Disturbance Effects on Self-Similarity in the Wake of a DrivAer Model Cranfield University

Format:

Book

Conference/Event

Author/Creator:

Rallapalli, Anurag, author.

Contributor:

Garry, Kevin

Proenca, Anderson

Conference Name:

WCX SAE World Congress Experience (2023-04-18 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource cm

Place of Publication:

Warrendale, PA SAE International 2023

Summary:

This study aims to provide an understanding of self-similarity in the turbulent wake generated by a Fastback DrivAer automotive model and assess the impact of upstream disturbances on the wake. The disturbances are generated using a circular cylinder placed five cylinder diameters upstream. Multiple cylinder-model' positions were tested by offsetting the lateral positioning of the cylinder with respect to the centreline of the model. Data was obtained at cross-planes in the wake going from 25% to 100% car length. Wind tunnel data has been obtained using a total pressure probe rake and a four-hole cobra probe. Data has also been obtained using RANS based simulations with k ε realisable turbulence model. Mean axial-component velocity profiles were analysed with momentum thickness (θ) and vorticity thickness (δω) used as the scaling parameters. It was seen that self-similarity marginally exists in the wake depending on the upstream conditions and the scaling parameter. Overall, vorticity thickness was seen to be better. Downstream, the mean profiles show a simpler collapse compared to the near wake. Understanding how deficit decay takes effect in the wake is useful to improve the aerodynamic performance of an automobile/motor car/ground vehicle. Therefore, establishing the similarity parameters presented in the work is an early step towards an analytical description of a turbulent wake model

Notes:

Vendor supplied data

Publisher Number:

2023-01-0014

Access Restriction:

Restricted for use by site license