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PressureOutflowBC.cpp
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3 // File: PressureOutflowBC.cpp
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31 //
32 // Description: Pressure outflow boundary condition
33 //
34 ///////////////////////////////////////////////////////////////////////////////
35 
36 #include "PressureOutflowBC.h"
37 
38 using namespace std;
39 
40 namespace Nektar
41 {
42 
43 std::string PressureOutflowBC::className = GetCFSBndCondFactory().
44  RegisterCreatorFunction("PressureOutflow",
45  PressureOutflowBC::create,
46  "Pressure outflow boundary condition.");
47 
48 PressureOutflowBC::PressureOutflowBC(
51  const Array<OneD, Array<OneD, NekDouble> >& pTraceNormals,
52  const int pSpaceDim,
53  const int bcRegion,
54  const int cnt)
55  : CFSBndCond(pSession, pFields, pTraceNormals, pSpaceDim, bcRegion, cnt)
56 {
57 }
58 
61  Array<OneD, Array<OneD, NekDouble> > &physarray,
62  const NekDouble &time)
63 {
64  int i, j;
65  int nTracePts = m_fields[0]->GetTrace()->GetNpoints();
66  int nVariables = physarray.num_elements();
67  int nDimensions = m_spacedim;
68 
69  const Array<OneD, const int> &traceBndMap
70  = m_fields[0]->GetTraceBndMap();
71 
72  NekDouble gammaMinusOne = m_gamma - 1.0;
73  NekDouble gammaMinusOneInv = 1.0 / gammaMinusOne;
74 
75  // Computing the normal velocity for characteristics coming
76  // from inside the computational domain
77  Array<OneD, NekDouble > Vn (nTracePts, 0.0);
78  Array<OneD, NekDouble > Vel(nTracePts, 0.0);
79  for (i = 0; i < nDimensions; ++i)
80  {
81  Vmath::Vdiv(nTracePts, Fwd[i+1], 1, Fwd[0], 1, Vel, 1);
82  Vmath::Vvtvp(nTracePts, m_traceNormals[i], 1, Vel, 1, Vn, 1, Vn, 1);
83  }
84 
85  // Computing the absolute value of the velocity in order to compute the
86  // Mach number to decide whether supersonic or subsonic
87  Array<OneD, NekDouble > absVel(nTracePts, 0.0);
88  m_varConv->GetAbsoluteVelocity(Fwd, absVel);
89 
90  // Get speed of sound
91  Array<OneD, NekDouble > pressure (nTracePts);
92  Array<OneD, NekDouble > soundSpeed(nTracePts);
93 
94  m_varConv->GetPressure(Fwd, pressure);
95  m_varConv->GetSoundSpeed(Fwd, pressure, soundSpeed);
96 
97  // Get Mach
98  Array<OneD, NekDouble > Mach(nTracePts, 0.0);
99  Vmath::Vdiv(nTracePts, Vn, 1, soundSpeed, 1, Mach, 1);
100  Vmath::Vabs(nTracePts, Mach, 1, Mach, 1);
101 
102  // Auxiliary variables
103  int e, id1, id2, npts, pnt;
104  NekDouble rhoeb;
105 
106  // Loop on the m_bcRegions
107  for (e = 0; e < m_fields[0]->GetBndCondExpansions()[m_bcRegion]->
108  GetExpSize(); ++e)
109  {
110  npts = m_fields[0]->GetBndCondExpansions()[m_bcRegion]->
111  GetExp(e)->GetTotPoints();
112  id1 = m_fields[0]->GetBndCondExpansions()[m_bcRegion]->
113  GetPhys_Offset(e) ;
114  id2 = m_fields[0]->GetTrace()->GetPhys_Offset(traceBndMap[m_offset+e]);
115 
116  // Loop on points of m_bcRegion 'e'
117  for (i = 0; i < npts; i++)
118  {
119  pnt = id2+i;
120 
121  // Subsonic flows
122  if (Mach[pnt] < 0.99)
123  {
124  // Kinetic energy calculation
125  NekDouble Ek = 0.0;
126  for (j = 1; j < nVariables-1; ++j)
127  {
128  Ek += 0.5 * (Fwd[j][pnt] * Fwd[j][pnt]) / Fwd[0][pnt];
129  }
130 
131  rhoeb = m_pInf * gammaMinusOneInv + Ek;
132 
133  // Partial extrapolation for subsonic cases
134  for (j = 0; j < nVariables-1; ++j)
135  {
136  (m_fields[j]->GetBndCondExpansions()[m_bcRegion]->
137  UpdatePhys())[id1+i] = Fwd[j][pnt];
138  }
139 
140  (m_fields[nVariables-1]->GetBndCondExpansions()[m_bcRegion]->
141  UpdatePhys())[id1+i] = rhoeb;
142  }
143  // Supersonic flows
144  else
145  {
146  for (j = 0; j < nVariables; ++j)
147  {
148  // Extrapolation for supersonic cases
149  (m_fields[j]->GetBndCondExpansions()[m_bcRegion]->
150  UpdatePhys())[id1+i] = Fwd[j][pnt];
151  }
152  }
153  }
154  }
155 }
156 
157 }
int m_spacedim
Space dimension.
Definition: CFSBndCond.h:90
void Vvtvp(int n, const T *w, const int incw, const T *x, const int incx, const T *y, const int incy, T *z, const int incz)
vvtvp (vector times vector plus vector): z = w*x + y
Definition: Vmath.cpp:442
STL namespace.
void Vdiv(int n, const T *x, const int incx, const T *y, const int incy, T *z, const int incz)
Multiply vector z = x/y.
Definition: Vmath.cpp:241
Array< OneD, MultiRegions::ExpListSharedPtr > m_fields
Array of fields.
Definition: CFSBndCond.h:86
boost::shared_ptr< SessionReader > SessionReaderSharedPtr
Definition: MeshPartition.h:51
void Vabs(int n, const T *x, const int incx, T *y, const int incy)
vabs: y = |x|
Definition: Vmath.cpp:424
CFSBndCondFactory & GetCFSBndCondFactory()
Declaration of the boundary condition factory singleton.
Definition: CFSBndCond.cpp:42
NekDouble m_pInf
Definition: CFSBndCond.h:97
static std::string npts
Definition: InputFld.cpp:43
Encapsulates the user-defined boundary conditions for compressible flow solver.
Definition: CFSBndCond.h:71
double NekDouble
NekDouble m_gamma
Parameters of the flow.
Definition: CFSBndCond.h:95
VariableConverterSharedPtr m_varConv
Auxiliary object to convert variables.
Definition: CFSBndCond.h:92
int m_offset
Offset.
Definition: CFSBndCond.h:103
virtual void v_Apply(Array< OneD, Array< OneD, NekDouble > > &Fwd, Array< OneD, Array< OneD, NekDouble > > &physarray, const NekDouble &time)
Array< OneD, Array< OneD, NekDouble > > m_traceNormals
Trace normals.
Definition: CFSBndCond.h:88
int m_bcRegion
Id of the boundary region.
Definition: CFSBndCond.h:101