Optimization and Computational Fluid Dynamics - Department of ...

174 René A. Van den Braembussche
low ˙m medium ˙m
high ˙m
Fig. 6.20 Midspan velocity vector of optimized diffuser
OF =(1− (wlow · Cplow + wmed · Cpmed + whigh · Cphigh))
+wlow · ωlow + wmed · ωmed + whigh · ωhigh
wlow =0.25 , wmed =0.5 , whigh =0.25
Using three different ANN, dedicated to the performance prediction at the
three operating points, improves the convergence.
The velocity vectors at midspan, shown in Fig. 6.20, indicate attached flow
at all three operating points and hence stable operation at low mass flow as
well as a large pressure rise at high mass flow.