CFD Review  
Serving the CFD Community with News, Articles, and Discussion
 
CFD Review

User Preferences
Site Sponsorship
Headline Feeds
Mobile Edition
Privacy Policy
Terms of Service
twitter

Submit a CFD Story

Site Sponsors
Siemens PLM Software
Pointwise: Reliable CFD meshing
Software Cradle

Tell a Friend
Help this site to grow by sending a friend an invitation to visit this site.

CFD News by Email
Did you know that you can get today's CFD Review headlines mailed to your inbox? Just log in and select Email Headlines Each Night on your User Preferences page.

 
CFD Analysis of a Solar Powered Car
Posted Mon August 07, 2006 @10:47AM
Print version Email story Tweet story
Application L.L.M. Boermans and J.P. Hemerik,
Delft University of Technology

Research students at the Department of Aerospace Engineering at the Delft University of Technology (DUT) used Gridgen to create high quality grids in their design of the solar powered cars Nuna 2 and Nuna 3 for the World Solar Challenge.

The World Solar Challenge is a biennial solar powered car race from Darwin to Adelaide, Australia. The 3000 kilometer race was won in 2001, 2003, and 2005 by cars designed by DUT.


Sponsor CFD Review

In 2001, DUTís car, the Nuna 1, won the race at a speed of 92 km/hr. DUTís second car, the Nuna 2 won the race in 2003 at a speed of 97 km/hr. After the 2003 race, DUT decided to use CFD and wind tunnel experiments to improve the design of their next car, the Nuna 3, for the 2005 race.

DUT choose to use Gridgen as the preprocessor for their CFD analysis. They used FLUENT as the flow solver and FIELDVIEW for postprocessing.

Gridgen was used to create a hybrid grid with prism blocks on the wall and unstructured blocks on the rest of the control volume. A higher density grid was applied under the belly pan and in the wake. The position of transition from laminar to turbulent boundary layer on the body and the wheel boxes is taken from oil flow patterns and stethoscope measurements on the wind tunnel model. In the calculations, the turbulent viscosity is switched off in the laminar zone. It turned out that CFD calculations with the k-ε realizable model produced lift and drag results comparable to the wind tunnel experiments.

Originally, the wheel fairings were causing an area of adverse pressure gradient on the belly pan. This triggered premature transition from laminar to turbulent flow, increasing skin friction drag.

On the design of the Nuna 3, the bump in the pressure distribution was eliminated by modifying the belly pan, allowing laminar flow up to the rear wheel fairing.

The students were also able to shape the front wheel fairings such that a suction effect is created under crosswind conditions that reduces pressure drag.

Using CFD, DUT once again was successful in designing the winning car in the 2005 World Solar Challenge. The Nuna 3 won the race with an average speed of 103 km/hr.

Delft Nuna3
The Delft Nuna3 solar powered car.

 

wheelbox grid
The hybrid grid around the car's wheelbox.

 

pressure distribution
Pressure distribution on the solar powered car.

 

[ Post Comment ]

COMSOL Users Conference Highlights Multiphysics Simulation | NASA Ames Purchases CEI's EnSight Gold  >

 

 
CFD Review Login
User name:

Password:

Create an Account

Related Links
  • ANSYS CFX
  • CD-adapco
  • CFDRC
  • Delft University of Technology
  • Exa
  • Fidap
  • FIELDVIEW
  • Fluent
  • Gridgen
  • Intelligent Light
  • Numeca
  • World Solar Challenge
  • More on Application
  • Also by nwyman
  • This discussion has been archived. No new comments can be posted.

    Many changes of mind and mood; do not hesitate too long. All content except comments
    ©2017, Viable Computing.

    [ home | submit story | search | polls | faq | preferences | privacy | terms of service | rss  ]