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Create unit test for ellipsoidal nose cone pressure drag interpolation

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This commit is contained in:
JoePfeiffer 2022-01-10 08:43:15 -07:00
parent a2341f4c18
commit 2e01115932
1 changed files with 39 additions and 0 deletions
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39
core/test/net/sf/openrocket/aerodynamics/SymmetricComponentCalcTest.java
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@ -103,4 +103,43 @@ public class SymmetricComponentCalcTest {
assertEquals(" SymmetricComponentCalc produces bad C_m: ", 0.0, forces.getCm(), EPSILON); assertEquals(" SymmetricComponentCalc produces bad C_m: ", 0.0, forces.getCm(), EPSILON);
} }
@Test
public void testEllipseNoseconeDrag() {
Rocket rocket = TestRockets.makeEstesAlphaIII();
NoseCone nose = (NoseCone)rocket.getChild(0).getChild(0);
// use an ellipsoidal nose cone with fineness ratio 5
nose.setType(Transition.Shape.ELLIPSOID);
nose.setLength(nose.getAftRadius() * 5.0);
SymmetricComponentCalc calcObj = new SymmetricComponentCalc( nose );
FlightConfiguration config = rocket.getSelectedConfiguration();
FlightConditions conditions = new FlightConditions(config);
conditions.setAOA(0.0);
WarningSet warnings = new WarningSet();
double frontalArea = Math.PI * nose.getAftRadius() * nose.getAftRadius();
// vvv TEST vvv
// these values from a reimplementation of the pressure cd calculation in python
// values at M = 0, 0.05, ... , 1.15
double cd[] = {
8.000392024269301e-07, 2.422001414621988e-06, 2.0098855921838474e-05,
8.295843903984836e-05, 0.000230425812213129, 0.0005104254351619708,
0.0009783566607446353, 0.0016963974152150677, 0.0027329880483111142,
0.004162427611715722, 0.006064546184601524, 0.008524431611715306,
0.011632196831399358, 0.01548277847481293, 0.020175760185344116,
0.02581521589534269, 0.032509569500239276, 0.04037146820686186,
0.04951766743137877, 0.06006892556095394, 0.07214990722137526,
0.08588909394291767, 0.10141870131021756, 0.11887460183385967 };
for (int i = 0; i < cd.length; i++) {
double m = i/20.0;
String buf = "SymmetricComponentCalc produces bad Cd at index " + i + "(m=" + m +")";
conditions.setMach(m);
double testcd = calcObj.calculatePressureDragForce(conditions, 0.0, 0.0, warnings) *
conditions.getRefArea() / frontalArea;
assertEquals(buf, cd[(int) Math.round(m*20)], testcd, EPSILON);
}
}
} }