#include <generalised_newtonian_constitutive_models.h>

Inheritance diagram for oomph::TanhProfileConstitutiveEquation< DIM >:

Public Member Functions
	TanhProfileConstitutiveEquation (double mu_inf_pt, double mu_0_pt, double alpha_pt, double critical_second_invariant_pt)

double	viscosity (const double &second_invariant_of_rate_of_strain_tensor)

double	dviscosity_dinvariant (const double &second_invariant_of_rate_of_strain_tensor)

Public Member Functions inherited from oomph::GeneralisedNewtonianConstitutiveEquation< DIM >
	GeneralisedNewtonianConstitutiveEquation ()
	Empty constructor. More...

virtual	~GeneralisedNewtonianConstitutiveEquation ()
	Empty virtual destructor. More...

Private Attributes
double *	Mu_inf_pt
	high shear rate viscosity More...

double *	Mu_0_pt
	zero shear rate viscosity More...

double *	Alpha_pt

double *	Critical_second_invariant_pt

Detailed Description

template<unsigned DIM>
class oomph::TanhProfileConstitutiveEquation< DIM >

A GeneralisedNewtonianConstitutiveEquation class defining a fluid following a tanh-profile

Constructor & Destructor Documentation

◆ TanhProfileConstitutiveEquation()

template<unsigned DIM>

oomph::TanhProfileConstitutiveEquation< DIM >::TanhProfileConstitutiveEquation	(	double *	mu_inf_pt,
		double *	mu_0_pt,
		double *	alpha_pt,
		double *	critical_second_invariant_pt
	)

inline

       : GeneralisedNewtonianConstitutiveEquation<DIM>(),
         Mu_inf_pt(mu_inf_pt),
         Mu_0_pt(mu_0_pt),
         Alpha_pt(alpha_pt),
         Critical_second_invariant_pt(critical_second_invariant_pt)
     {
     }

Member Function Documentation

◆ dviscosity_dinvariant()

template<unsigned DIM>

double oomph::TanhProfileConstitutiveEquation< DIM >::dviscosity_dinvariant ( const double & second_invariant_of_rate_of_strain_tensor )

inlinevirtual

Function returning the derivative of the viscosity w.r.t. the second invariant of the rate of strain tensor For Newtonian behaviour this returns 0.0

Implements oomph::GeneralisedNewtonianConstitutiveEquation< DIM >.

     {
       // Pre-multiply the second invariant with +/-1 depending on whether it's
       // positive or not
       double sign = -1.0;
       if (second_invariant_of_rate_of_strain_tensor >= 0.0)
       {
         sign = 1.0;
       }
  
       return -sign * ((*Mu_0_pt) - (*Mu_inf_pt)) * 10.0 /
              (2.0 * (*Critical_second_invariant_pt)) * 1.0 /
              cosh(((*Critical_second_invariant_pt) -
                    sign * second_invariant_of_rate_of_strain_tensor) *
                   (*Alpha_pt)) *
              1.0 /
              cosh(((*Critical_second_invariant_pt) -
                    sign * second_invariant_of_rate_of_strain_tensor) *
                   (*Alpha_pt));
     }

References Eigen::bfloat16_impl::cosh(), oomph::TanhProfileConstitutiveEquation< DIM >::Critical_second_invariant_pt, and SYCL::sign().

◆ viscosity()

template<unsigned DIM>

double oomph::TanhProfileConstitutiveEquation< DIM >::viscosity ( const double & second_invariant_of_rate_of_strain_tensor )

inlinevirtual

Function implementing the constitutive model Input: second invariant of the rate of strain Output: the viscosity For Newtonian behaviour this returns 1

Implements oomph::GeneralisedNewtonianConstitutiveEquation< DIM >.

     {
       // Pre-multiply the second invariant with +/-1 depending on whether it's
       // positive or not
       double sign = -1.0;
       if (second_invariant_of_rate_of_strain_tensor >= 0.0)
       {
         sign = 1.0;
       }
  
       return ((*Mu_0_pt) - (*Mu_inf_pt)) / 2.0 *
                tanh(((*Critical_second_invariant_pt) -
                      sign * second_invariant_of_rate_of_strain_tensor) *
                     (*Alpha_pt)) -
              ((*Mu_0_pt) - (*Mu_inf_pt)) / 2.0 + (*Mu_0_pt);
     }