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Homework Help: Drag calculation based on kinetic theory, flux

  1. Feb 2, 2010 #1
    1. The problem statement, all variables and given/known data
    A flat plate is orbiting at an altitude of 250 km around the earth, at an angle of attack Β=45 degrees. Assume that the atmosphere is composed of only atomic oxygen which reflect from the surface diffusely. Calculate the lift and drag if it has an area of 10 M2.

    Cd~2.2
    n=1x1015/m3
    T=975 K
    Β=45 degrees
    A=10 m2
    mo=2.67 x 10-26 kg
    vo=7.8 x 103 m/s
    Θ=Τ=1
    Θ upper=135 degrees
    Θ lower=45 degrees


    2. Relevant equations

    I cannot use the basic CD, CL equations. I need to use a set of boundary condition equations based on kinetic theory.
    CL=4Ε/√(Π) *vth[/SUB/vd * sin(Β)*cos(Β) exp (-vd*sin(Β/vth[/SUB)^2)+....etc
    and a similar equation for CD



    3. The attempt at a solution

    I have drifting gas equations, stationary gas equations and a ton more.

    Pn/Pinf=((1+Ε)/sqrt(Π))*(vd cos theta/vth)....

    Τ/Pinf=(1-Ε)/sqrt(Π)*vd sin(Θ)...

    q/mninf(2kTinf/m)^(3/2)=alphac(1-Ε)/(4*sqrtΠ)...

    Any help here?
    Thanks!
     
  2. jcsd
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