oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM > Class Template Reference

#include <generalised_newtonian_constitutive_models.h>

Inheritance diagram for oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >:

Public Member Functions
	HerschelBulkleyPapRegConstitutiveEquation (double *yield_stress_pt, double *flow_index_pt, double *exponential_parameter_pt)
double	viscosity (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...
virtual double	dviscosity_dinvariant (const double &second_invariant_of_rate_of_strain_tensor)=0

Private Attributes
double *	Yield_stress_pt
	Yield stress tau_y. More...
double *	Flow_index_pt
	Power law index n. More...
double *	Exponential_parameter_pt
	Regularisation parameter m >> 1. More...

Detailed Description

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

A GeneralisedNewtonianConstitutiveEquation class defining a Herschel-Bulkley fluid using Papanastasiou's (1987) regularisation

Constructor & Destructor Documentation

HerschelBulkleyPapRegConstitutiveEquation()

template<unsigned DIM>

oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::HerschelBulkleyPapRegConstitutiveEquation ( double *  yield_stress_pt, double *  flow_index_pt, double *  exponential_parameter_pt  )

inline

      : GeneralisedNewtonianConstitutiveEquation<DIM>(),
        Yield_stress_pt(yield_stress_pt),
        Flow_index_pt(flow_index_pt),
        Exponential_parameter_pt(exponential_parameter_pt)
    {
    }

Member Function Documentation

viscosity()

template<unsigned DIM>

double oomph::HerschelBulkleyPapRegConstitutiveEquation< 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 >.

    {
      // Calculate magnitude of the rate of strain tensor
      double measure_of_rate_of_strain =
        sqrt(std::fabs(second_invariant_of_rate_of_strain_tensor));
 
      return (1.0 - exp(-2.0 * (*Exponential_parameter_pt) *
                        measure_of_rate_of_strain)) /
               (2.0 * measure_of_rate_of_strain) * (*Yield_stress_pt) +
             (1.0 - exp(-2.0 * (*Exponential_parameter_pt) *
                        measure_of_rate_of_strain)) /
               (2.0 * measure_of_rate_of_strain) *
               pow((2.0 * measure_of_rate_of_strain), *Flow_index_pt);
    }

References Eigen::bfloat16_impl::exp(), oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::Exponential_parameter_pt, boost::multiprecision::fabs(), oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::Flow_index_pt, Eigen::bfloat16_impl::pow(), sqrt(), and oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::Yield_stress_pt.

Member Data Documentation

Exponential_parameter_pt

template<unsigned DIM>

double* oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::Exponential_parameter_pt

private

Regularisation parameter m >> 1.

Referenced by oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::viscosity().

Flow_index_pt

template<unsigned DIM>

double* oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::Flow_index_pt

private

Power law index n.

Referenced by oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::viscosity().

Yield_stress_pt

template<unsigned DIM>

double* oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::Yield_stress_pt

private

Yield stress tau_y.

Referenced by oomph::HerschelBulkleyPapRegConstitutiveEquation< DIM >::viscosity().

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The documentation for this class was generated from the following file:

• generalised_newtonian_constitutive_models.h