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ES174 Car Aerodynamics

Aims

    • To learn design philosophy and design procedures by using CFD package;
    • To provide an introduction to computational fluid dynamics for car aerodynamics through an open-ended design project

    Objectives

      • To know basic concepts of fluid dynamics and car aerodynamics;
      • To use a commercial CFD software (COSMOSFlowWorks) to solve engineering fluid problems;
      • To appreciate the potentials and limitations of CFD as part of the design process;
      • To perform basic analysis of the CFD results and optimasation.

      Procedures

      1. Prepare two 3-D car prototype-models and a wind tunnel model using Solidworks;
        • Model A: build a car model of your own choice.
        • Model B: A box-shaped car with the same dimensions (length, width and height),
        • Build a wind tunnel with lids on both end.
      2. Assemble the car with the wind tunnel;
        • Avoid point contact between the car wheels and the tunnel floor.
      3. Create a project using CosmosFlowWork;
      4. Run simulations for the flow field around the car;
        • Find the drag force
        • Calculate drag coefficients
        • Plot the these values against velocity (converted to miles per hour)
      5. Analyse the results (aerodynamic performances of your car) and make improvement to the design of your car body;
      6. Compare two simulation results to find the effect of the car design on aerodynamics;
      7. Run further simulations, if necessary, to improve aerodynamics;
      8. Write up your report.

      Report

      • You will hand in an individual report by the end of Week 22 (2pm, Friday 29 February 2008);
      • The total length of the report is 4 pages of A4 paper.
      • How to write a report!
      • You need to run three simulations for this exercise.
        • Test simulation with either Model A or Model B with a lower resolution (Program running time should be no longer than 30 minutes).
        • Main simulation with Model A (Program running time can take up to 3 hours).
        • Main simulation with Model B with almost identical conditions.
      • The report must include evidence of your achievements together with analysis and discussion based on fluid dynamic knowledge;
      • NO accompanying CD is required.

      The Brief

       

      Time Management

      Credit: 4 CATS - The average students input time is 40 hours.

      • Contact hours including Briefing Sessions (3hr) and Lab sessions (6hr) - 10hr,

      • Choosing your model car & gathering information - 5hr,

      • Building your own model car (SolidWorks) - 5hr,

      • CosmosFlowWorks simulations - 15hr,

      • Writing up the report - 5hr.