def calculateCoeffs(self):
"""
If forces exist, the respective coefficients are calculated accordingly.
Otherwise a ValueError is raised.
:param L: Reference length
:type L: float
:param A: Reference area
:type A: float
"""
self.uInf = Utilities.mag(self.inletVelocity)
self.Re = FlowProperties.Re(L=self.L, u=self.uInf)
self.Fr = FlowProperties.Fr(L=self.L, u=self.uInf)
if self.forces:
self.t = self.forces[0]
self.resistances['RF'] = self.direction * self.forces[
abs(self.direction) + 3]
self.resistances['RT'] = self.resistances['RF'] +\
self.direction*self.forces[abs(self.direction)]
self.resistances['CF'] = Resistance.forceCoeff(
self.resistances['RF'], self.A, u=self.uInf)
self.resistances['CT'] = Resistance.forceCoeff(
self.resistances['RT'], self.A, u=self.uInf)
else:
raise ValueError
def testVelToFr(self):
"""
Tests the conversion from velocity to Froude number
"""
for vel, Froude in self.vFr:
result = FlowProperties.Fr(u=vel, L=1.0, nu=Constants.water['nu'])
self.assertEqual(Froude, result)
def forceCoeff(F, Swett, u=None, Re=None, Fr=None, **kwargs):
"""
Calculates the force coefficient by
..math::
C = \\frac{F}{0.5\\rho S_{wett} u^2}
:param F: Force
:type F: float
:param Swett: Wetted surface area
:type Swett: float
:param u: Velocity
:type u: float
:param Re: Reynoldsnumber
:type Re: float
:param Fr: Froudenumber
:type Fr: float
:rtype: float
:Author: Jens Hoepken <*****@*****.**>
"""
if not 'rho' in kwargs.iterkeys():
rho = Constants.water['rho']
else:
rho = kwargs['rho']
if Re:
u = FlowProperties.Re(Re=Re, L=kwargs['L'])
elif Fr:
u = FlowProperties.Fr(Fr=Fr, L=kwargs['L'])
return F / (0.5 * rho * Swett * u**2)
def testFrToVel(self):
"""
Tests the conversion from Froude nubmer to velocity
"""
for vel, Froude in self.vFr:
result = FlowProperties.Fr(Fr=Froude,
L=1.0,
nu=Constants.water['nu'])
self.assertEqual(vel, result)
def updateInletVelocity(self):
"""
Reads and updates the inlet velocity. This has to be done without
pyFoam, as this takes *ages* for a file with precalculated
velocities.
"""
inletFound = False
with open(join(self.name, self.first, 'U'), 'r') as bc:
for line in bc:
for patchI in self.inletPatch:
if patchI in line:
inletFound = True
if inletFound:
if "uniform" in line:
vIn = line
break
numberRe = compile(r"[+-]? *(?:\d+(?:\.\d*)?|\.\d+)(?:[eE][+-]?\d+)?")
self.inletVelocity = [float(uI) for uI in findall(numberRe, vIn)]
self.uInf = Utilities.mag(self.inletVelocity)
self.Re = FlowProperties.Re(L=self.L, u=self.uInf)
self.Fr = FlowProperties.Fr(L=self.L, u=self.uInf)
