From: Guido Kanschat <dr.guido.kanschat@gmail.com>
Date: Wed, 26 Sep 2007 04:03:31 +0000 (+0000)
Subject: fix Kovasnzay flow
X-Git-Tag: v8.0.0~9818
X-Git-Url: https://gitweb.dealii.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=819f611be6fa57f99e62f0283b1d1eecc1b41872;p=dealii.git

fix Kovasnzay flow

git-svn-id: https://svn.dealii.org/trunk@15244 0785d39b-7218-0410-832d-ea1e28bc413d
---

diff --git a/deal.II/base/include/base/flow_function.h b/deal.II/base/include/base/flow_function.h
index ca49d35955..794c1f9dbd 100644
--- a/deal.II/base/include/base/flow_function.h
+++ b/deal.II/base/include/base/flow_function.h
@@ -226,7 +226,6 @@ namespace Functions
 				     std::vector<std::vector<Tensor<1,2> > >& gradients) const;
       virtual void vector_laplacians (const std::vector<Point<2> > &points,
 				      std::vector<std::vector<double> >   &values) const;
-
     private:
 				       /// The auxiliary function Psi.
       double Psi(double phi) const;
@@ -286,9 +285,11 @@ namespace Functions
       virtual void vector_laplacians (const std::vector<Point<2> > &points,
 				      std::vector<std::vector<double> >   &values) const;
 
+				       /// The value of lambda.
+      double lambda () const;
     private:
       const double Reynolds;
-      double lambda;
+      double lbda;
       double p_average;
       const bool stokes;
   };
diff --git a/deal.II/base/source/flow_function.cc b/deal.II/base/source/flow_function.cc
index 8c219bb703..74412a12b0 100644
--- a/deal.II/base/source/flow_function.cc
+++ b/deal.II/base/source/flow_function.cc
@@ -613,7 +613,7 @@ namespace Functions
     long double r2 = Reynolds/2.;
     long double b = 4*M_PI*M_PI;
     long double l = -b/(r2+std::sqrt(r2*r2+b));
-    lambda = l;
+    lbda = l;
 				     // mean pressure for a domain
 				     // spreading from -.5 to 1.5 in
 				     // x-direction
@@ -640,11 +640,11 @@ namespace Functions
 	const Point<2>& p = points[k];
 	const double x = p(0);
 	const double y = 2. * deal_II_numbers::PI * p(1);
-	const double elx = std::exp(lambda*x);
+	const double elx = std::exp(lbda*x);
 	
 	values[0][k] = 1. - elx * cos(y);
-	values[1][k] = .5 / deal_II_numbers::PI * lambda * elx * sin(y);
-	values[2][k] = .5 * elx * elx - p_average - this->mean_pressure;
+	values[1][k] = .5 / deal_II_numbers::PI * lbda * elx * sin(y);
+	values[2][k] = -.5 * elx * elx + p_average - this->mean_pressure;
       }
   }
   
@@ -653,29 +653,28 @@ namespace Functions
     const std::vector<Point<2> >& points,
     std::vector<std::vector<Tensor<1,2> > >& gradients) const
   {
-    Assert(false, ExcNotImplemented());
     unsigned int n = points.size();
     
-    Assert (gradients.size() == n, ExcDimensionMismatch(gradients.size(), n));
-    Assert (gradients[0].size() >= this->n_components,
-	    ExcDimensionMismatch(gradients[0].size(), this->n_components));
+    Assert (gradients.size() == 3, ExcDimensionMismatch(gradients.size(), 3));
+    Assert (gradients[0].size() == n,
+	    ExcDimensionMismatch(gradients[0].size(), n));
     
     for (unsigned int i=0;i<n;++i)
       {
 	const double x = points[i](0);
 	const double y = points[i](1);
 	
-	const double elx = std::exp(lambda*x);
+	const double elx = std::exp(lbda*x);
 	const double cy = cos(2*M_PI*y);
 	const double sy = sin(2*M_PI*y);
 	
 					 // u
-	gradients[0][i][0] = -lambda*elx*cy;
-	gradients[0][i][1] = 2*M_PI*elx*sy;
-	gradients[1][i][0] = lambda*lambda/(2*M_PI)*elx*sy;
-	gradients[1][i][1] =lambda*elx*cy;
+	gradients[0][i][0] = -lbda*elx*cy;
+	gradients[0][i][1] = 2. * deal_II_numbers::PI*elx*sy;
+	gradients[1][i][0] = lbda*lbda/(2*M_PI)*elx*sy;
+	gradients[1][i][1] =lbda*elx*cy;
 					 // p
-	gradients[2][i][0] = -lambda*elx*elx;
+	gradients[2][i][0] = -lbda*elx*elx;
 	gradients[2][i][1] = 0.;
     }
   }
@@ -699,13 +698,13 @@ namespace Functions
 	    const Point<2>& p = points[k];
 	    const double x = p(0);
 	    const double y = zp * p(1);
-	    const double elx = std::exp(lambda*x);
+	    const double elx = std::exp(lbda*x);
 	    const double u  = 1. - elx * cos(y);
-	    const double ux = -lambda * elx * cos(y);
+	    const double ux = -lbda * elx * cos(y);
 	    const double uy = elx * zp * sin(y);
-	    const double v  = lambda/zp * elx * sin(y);
-	    const double vx = lambda*lambda/zp * elx * sin(y);
-	    const double vy = zp*lambda/zp * elx * cos(y);
+	    const double v  = lbda/zp * elx * sin(y);
+	    const double vx = lbda*lbda/zp * elx * sin(y);
+	    const double vy = zp*lbda/zp * elx * cos(y);
 	    
 	    values[0][k] = u*ux+v*uy;
 	    values[1][k] = u*vx+v*vy;
@@ -720,6 +719,11 @@ namespace Functions
       }
   }
   
+  double
+  Kovasznay::lambda () const
+  {
+    return lbda;
+  }