6fe02cae14d9574a15dea08640cf4e8db029c4d6,trunk/SUAVE/Methods/Aerodynamics/Supersonic_Zero/Drag/parasite_drag_propulsor.py,,parasite_drag_propulsor,#Any#Any#Any#,21

Before Change

    
    sb_mask = (Mc <= Mdiv)
    tn_mask = ((Mc > Mdiv) & (Mc < 1.05))
    sp_mask = (Mc >= 1.05)
    
    k_prop[sb_mask] = k_prop_sub
    // basic interpolation for transonic
    k_prop[tn_mask] = (k_prop_sup-k_prop_sub)*(Mc[tn_mask]-Mdiv[tn_mask])/(1.05-Mdiv[tn_mask]) + k_prop_sub
    k_prop[sp_mask] = k_prop_sup
    
    // --------------------------------------------------------
    // find the final result    
    propulsor_parasite_drag = k_prop * cf_prop * Swet / Sref  

After Change

    
    // conditions
    freestream = conditions.freestream
    Mc = freestream.mach_number
    Tc = freestream.temperature    
    re = freestream.reynolds_number

    // reynolds number
    Re_prop = re*l_prop
    
    // skin friction coefficient
    cf_prop, k_comp, k_reyn = compressible_turbulent_flat_plate(Re_prop,Mc,Tc)


    //k_prop = np.array([[0.0]]*len(Mc))
    
    // form factor according to Raymer equation (pg 283 of Aircraft Design: A Conceptual Approach)
    k_prop_sub = 1. + 0.35 / (float(l_prop)/float(d_prop)) 
    
    // for supersonic flow (http://adg.stanford.edu/aa241/drag/BODYFORMFACTOR.HTML)
    k_prop_sup = 1.
    
    trans_spline = Cubic_Spline_Blender(low_mach_cutoff,high_mach_cutoff)
    h00 = lambda M:trans_spline.compute(M)
    
    k_prop = k_prop_sub*(h00(Mc)) + k_prop_sup*(1-h00(Mc))
    
    // --------------------------------------------------------
    // find the final result    
    propulsor_parasite_drag = k_prop * cf_prop * Swet / Sref  

Instances