Merge pull request #354 from LRossman/lrossman-dev

Avoid possible divide by zero in hydcoeffs.c
This commit is contained in:
Lew Rossman
2018-12-06 10:56:08 -05:00
committed by GitHub

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@@ -799,21 +799,32 @@ void pumpcoeff(Project *pr, int k)
// Adjust head loss coefficients for pump speed
h0 = SQR(setting) * pump->H0;
n = pump->N;
if (ABS(n - 1.0) < TINY) n = 1.0;
r = pump->R * pow(setting, 2.0 - n);
// Compute head loss and its gradient
// ... use linear approx. to pump curve for small flows
qa = pow(hyd->RQtol / n / r, 1.0 / (n - 1.0));
if (q <= qa)
// ... pump curve is nonlinear
if (n != 1.0)
{
hgrad = hyd->RQtol;
hloss = h0 + hgrad * hyd->LinkFlow[k];
// ... use linear approx. to pump curve for small flows
qa = pow(hyd->RQtol / n / r, 1.0 / (n - 1.0));
if (q <= qa)
{
hgrad = hyd->RQtol;
hloss = h0 + hgrad * hyd->LinkFlow[k];
}
// ... use original pump curve for normal flows
else
{
hgrad = n * r * pow(q, n - 1.0);
hloss = h0 + hgrad * hyd->LinkFlow[k] / n;
}
}
// ... use original pump curve for normal flows
// ... pump curve is linear
else
{
hgrad = n * r * pow(q, n - 1.0);
hloss = h0 + hgrad * hyd->LinkFlow[k] / n;
hgrad = r;
hloss = h0 + hgrad * hyd->LinkFlow[k];
}
}