diff --git a/src/implementation/core/tnlString.cpp b/src/implementation/core/tnlString.cpp
index 01dabf525a466acc917013d6a7ade61498cd32fd..d128923e3df1f13de951ed0090473ab2336b885c 100644
--- a/src/implementation/core/tnlString.cpp
+++ b/src/implementation/core/tnlString.cpp
@@ -81,7 +81,7 @@ tnlString :: ~tnlString()
 {
    if( string ) delete[] string;
 }
-//---------------------------------------------------------------------------
+
 void tnlString :: setString( const char* c, int prefix_cut_off, int sufix_cut_off )
 {
    if( ! c )
@@ -111,27 +111,27 @@ void tnlString :: setString( const char* c, int prefix_cut_off, int sufix_cut_of
    memcpy( string, c + Min( c_len, prefix_cut_off ), sizeof( char ) * ( _length ) );
    string[ _length ] = 0;
 }
-//---------------------------------------------------------------------------
+
 const char& tnlString :: operator[]( int i ) const
 {
    tnlAssert( i >= 0 && i < length,
               cerr << "Accessing char outside the string." );
    return string[ i ];
 }
-//---------------------------------------------------------------------------
+
 char& tnlString :: operator[]( int i )
 {
    tnlAssert( i >= 0 && i < length,
               cerr << "Accessing char outside the string." );
    return string[ i ];
 }
-//---------------------------------------------------------------------------
+
 tnlString& tnlString :: operator = ( const tnlString& str )
 {
    setString( str. getString() );
    return * this;
 }
-//---------------------------------------------------------------------------
+
 tnlString& tnlString :: operator += ( const char* str )
 {
    if( str )
@@ -151,7 +151,7 @@ tnlString& tnlString :: operator += ( const char* str )
    }
    return * this;
 }
-//---------------------------------------------------------------------------
+
 tnlString& tnlString :: operator += ( const char str )
 {
    int len1 = strlen( string );
@@ -172,22 +172,22 @@ tnlString& tnlString :: operator += ( const char str )
 
    return * this;
 }
-//---------------------------------------------------------------------------
+
 tnlString& tnlString :: operator += ( const tnlString& str )
 {
    return operator += ( str. getString() );
 }
-//---------------------------------------------------------------------------
+
 tnlString tnlString :: operator + ( const tnlString& str )
 {
    return tnlString( *this ) += str;
 }
-//---------------------------------------------------------------------------
+
 tnlString tnlString :: operator + ( const char* str )
 {
    return tnlString( *this ) += str;
 }
-//---------------------------------------------------------------------------
+
 bool tnlString :: operator == ( const tnlString& str ) const
 {
    assert( string && str. string );
@@ -197,12 +197,12 @@ bool tnlString :: operator == ( const tnlString& str ) const
       return true;
    return false;
 }
-//---------------------------------------------------------------------------
+
 bool tnlString :: operator != ( const tnlString& str ) const
 {
    return ! operator == ( str );
 }
-//---------------------------------------------------------------------------
+
 bool tnlString :: operator == ( const char* str ) const
 {
    //cout << ( void* ) string << " " << ( void* ) str << endl;
diff --git a/src/implementation/schemes/euler/fvm/tnlLaxFridrichs_impl.h b/src/implementation/schemes/euler/fvm/tnlLaxFridrichs_impl.h
index f564e08d501fc0a2bdb42de6f33177ccf856866e..8cfe1c728e5ddac2f66ef5c1083b76367b446777 100644
--- a/src/implementation/schemes/euler/fvm/tnlLaxFridrichs_impl.h
+++ b/src/implementation/schemes/euler/fvm/tnlLaxFridrichs_impl.h
@@ -366,9 +366,10 @@ template< typename Real,
           typename Index,
           typename PressureGradient >
 void tnlLaxFridrichs< tnlGrid< 2, Real, Device, Index, tnlIdenticalGridGeometry >, PressureGradient  > :: getExplicitRhs( const IndexType centralVolume,
-                                                                                                RealType& rho_t,
-                                                                                                RealType& rho_u1_t,
-                                                                                                RealType& rho_u2_t ) const
+                                                                                                                          RealType& rho_t,
+                                                                                                                          RealType& rho_u1_t,
+                                                                                                                          RealType& rho_u2_t,
+                                                                                                                          const RealType& tau ) const
 {
    tnlAssert( mesh, cerr << "No mesh has been binded with the Lax-Fridrichs scheme." );
    tnlAssert( pressureGradient, cerr << "No pressure gradient was set in the the Lax-Fridrichs scheme." )
@@ -391,7 +392,7 @@ void tnlLaxFridrichs< tnlGrid< 2, Real, Device, Index, tnlIdenticalGridGeometry
    const RealType u1_w = rho_u1[ w ] / regularize( rho[ w ] );
    const RealType u2_n = rho_u2[ n ] / regularize( rho[ n ] );
    const RealType u2_s = rho_u2[ s ] / regularize( rho[ s ] );
-   rho_t = this -> viscosityCoefficient * 0.25 * ( rho[ e ] + rho[ w ] + rho[ s ] + rho[ n ] - 4.0 * rho[ c ] )
+   rho_t = this -> viscosityCoefficient / tau * 0.25 * ( rho[ e ] + rho[ w ] + rho[ s ] + rho[ n ] - 4.0 * rho[ c ] )
                - ( rho[ e ] * u1_e - rho[ w ] * u1_w ) / ( 2.0 * hx )
                - ( rho[ n ] * u2_n - rho[ s ] * u2_s ) / ( 2.0 * hy );
 
@@ -404,14 +405,14 @@ void tnlLaxFridrichs< tnlGrid< 2, Real, Device, Index, tnlIdenticalGridGeometry
    /****
     * ( rho * u1 )_t + ( rho * u1 * u1 )_x + ( rho * u1 * u2 )_y - p_x =  0
     */
-   rho_u1_t = this -> viscosityCoefficient * 0.25 * ( rho_u1[ e ] + rho_u1[ w ] + rho_u1[ s ] + rho_u1[ n ] - 4.0 * rho_u1[ c ] )
+   rho_u1_t = this -> viscosityCoefficient / tau * 0.25 * ( rho_u1[ e ] + rho_u1[ w ] + rho_u1[ s ] + rho_u1[ n ] - 4.0 * rho_u1[ c ] )
                    - ( rho_u1[ e ] * u1_e - rho_u1[ w ] * u1_w ) / ( 2.0 * hx )
                    - ( rho_u1[ n ] * u2_n - rho_u1[ s ] * u2_s ) / ( 2.0 * hy )
                    - grad_p. x();
    /****
     * ( rho * u2 )_t + ( rho * u2 * u1 )_x + ( rho * u2 * u2 )_y - p_y =  0
     */
-   rho_u2_t = this -> viscosityCoefficient * 0.25 * ( rho_u2[ e ] + rho_u2[ w ] + rho_u2[ s ] + rho_u2[ n ] - 4.0 * rho_u2[ c ] )
+   rho_u2_t = this -> viscosityCoefficient / tau * 0.25 * ( rho_u2[ e ] + rho_u2[ w ] + rho_u2[ s ] + rho_u2[ n ] - 4.0 * rho_u2[ c ] )
                    - ( rho_u2[ e ] * u1_e - rho_u2[ w ] * u1_w ) / ( 2.0 * hx )
                    - ( rho_u2[ n ] * u2_n - rho_u2[ s ] * u2_s ) / ( 2.0 * hy )
                    - grad_p. y();