Numerical Analysis on the Transitional Mechanism of the Wake Structure of the Ahmed Body Tokyo City University

Format:

Conference/Event

Author/Creator:

Kobayashi, Kobayashi, author.

Contributor:

Hashizume, Yoshimitsu

Kasai, Akira

Katoh, Daichi

Kohri, Itsuhei

Nasu, Takayoshi

Conference Name:

SAE 2016 World Congress and Exhibition (2016-04-12 : Detroit, Michigan, United States)

Language:

English

Physical Description:

1 online resource

Place of Publication:

Warrendale, PA SAE International 2016

Summary:

AbstractThe critical change in drag occurring on the Ahmed body when the slanted base has an angle of 30° is due to a transition in the wake structure. In a previous study on flow analysis across the Ahmed body, we investigated the unsteady wake experimentally using hot-wire and particle image velocimetry measurements. However, because the experimental analysis yielded limited data, the spatially unsteady wake behaviour, interaction between the trailing vortex and transverse vortices (up/downwash), and flow mechanism near the body were not discussed sufficiently. In this study, the unsteady wake structures were analysed computationally using computational fluid dynamics to understand these issues, and the hypothesis was tested. The slant angle was 27.5°, which is identical to that in the experiment and corresponds to a high drag condition indicated experimentally. Spatially unsteady fluctuation structures were clarified, and the relation between the structures and the critical change in drag was discussed. On the basis of these discussion and previous knowledge, the mechanism generating the huge fluctuation structure of the downwash, which is considered to be strongly related to the critical change in drag, was revealed

Notes:

Vendor supplied data

Publisher Number:

2016-01-1592

Access Restriction:

Restricted for use by site license