protected void CalculateTTR()
{
//calculate TTR at design point first
// Don't overwrite th0 and th1
EngineThermodynamics ambientTherm = EngineThermodynamics.StandardConditions(false);
ambientTherm.T = T_d;
EngineThermodynamics inletTherm = ambientTherm.ChangeReferenceFrameMach(M_d);
// Note that this work is negative
// Different mass flows between compressor, turbine, and bypass automatically taken care of by MassRatio
double compressorWork;
th3 = inletTherm.AdiabaticProcessWithPressureRatio(CPR, out compressorWork, efficiency: eta_c);
double fanWork = 0d;
if (BPR > 0d)
{
th2 = inletTherm.AdiabaticProcessWithPressureRatio(FPR, out fanWork, efficiency: eta_c);
fanWork *= BPR;
fanWorkConstant = fanWork / compressorWork;
}
double turbineWork = compressorWork + fanWork;
th4 = th3.AddFuelToTemperature(Tt4, h_f);
th5 = th4.AdiabaticProcessWithWork(turbineWork, efficiency: eta_t);
TTR = th5.T / th4.T;
}