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ot

OpenTerrace class.

Source code in openterrace/openterrace.py 
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class ot:
    """OpenTerrace class."""
    def __init__(self, t_end:float=None, dt:float=None, sim_name:str=None):
        """Initialise with various control parameters.

        Args:
            t_end (float): End time in s
            dt (float): Time step size in s
        """
        self.t_start = 0
        self.t_end = t_end
        self.dt = dt
        self.coupling = []
        self.flag_coupling = False
        self.sim_name = sim_name

    class Phase:
        instances = []
        """Main class to define either the fluid or bed phase."""
        def __init__(self, n:int=None, n_other:int=1, type:str=None):
            """Initialise a phase with number of control points and type.

            Args:
                n_self (int): Number of discretisations for the given phase
                n_other (int): Number of discretisations for the other phase
                type (str): Type of phase
            """
            self.__class__.instances.append(self)
            self.n = n
            self.n_other = n_other

            self.phi = 1

            self.bcs = []
            self.sources = []

            self._flag_save_data = False

            self.type = type
            self._valid_inputs(type)

        def _valid_inputs(self, type:str=None):
            """Gets valid domain and substances depending on type of phase.
            """
            self.valid_domains = globals()['domains'].__all__
            self.valid_substances = globals()[type+'_substances'].__all__

        def select_substance_on_the_fly(self, cp:float=None, rho:float=None, k:float=None):
            """Defines and selects a new substance on-the-fly. This is useful for defining a substance for testing purposes with temperature independent properties.

            Args:
                cp (float): Specific heat capacity in J/(kg K)
                rho (float): Density in kg/m^3
                k (float): Thermal conductivity in W/(m K)
            """
            class dummy:
                pass
            self.fcns = dummy()
            self.fcns.h = lambda T: np.ones_like(T)*T*cp
            self.fcns.T = lambda h: np.ones_like(h)*h/cp
            self.fcns.cp = lambda h: np.ones_like(h)*cp
            self.fcns.k = lambda h: np.ones_like(h)*k
            self.fcns.rho = lambda h: np.ones_like(h)*rho

        def select_substance(self, substance:str=None):
            """Selects one of the predefined substancers.

            Args:
                substance (str): Substance name
            """
            if not substance:
                raise Exception("Keyword 'substance' not specified.")
            if not substance in self.valid_substances:
                raise Exception(substance+" specified as "+self.type+" substance. Valid "+self.type+" substances are:", self.valid_substances)
            self.fcns = getattr(globals()[self.type+'_substances'], substance)

        def select_domain_shape(self, domain:str=None, **kwargs):
            """Select domain shape and initialise constants."""
            kwargs['n'] = self.n
            if not domain:
                raise Exception("Keyword 'domain' not specified.")
            if not domain in globals()['domains'].__all__:
                raise Exception("domain \'"+domain+"\' specified. Valid options for domain are:", self.valid_domains)
            self.domain = getattr(globals()['domains'], domain)
            self.domain.type = domain
            self.domain.validate_input(kwargs, domain)
            self.domain.shape = self.domain.shape(kwargs)
            self.domain.node_pos = self.domain.node_pos(kwargs)
            self.domain.dx = self.domain.dx(kwargs)
            self.domain.A = self.domain.A(kwargs)
            self.domain.V = self.domain.V(kwargs)

        def select_porosity(self, phi:float=1):
            """Select porosity from 0 to 1, e.g. filling the domain with the phase up to a certain degree."""
            self.domain.V = self.domain.V*phi
            self.phi = phi

        def select_schemes(self, diff:str=None, conv:str=None):
            """Imports the specified diffusion and convection schemes."""

            if self.domain.type == 'lumped':
                raise Exception("'lumped' has been selected as domain type. Please don't specify a discretisation scheme.")

            if diff is not None:
                try:
                    self.diff = getattr(getattr(globals()['diffusion_schemes'], diff), diff)
                except:
                    raise Exception("Diffusion scheme \'"+diff+"\' specified. Valid options for diffusion schemes are:", diffusion_schemes.__all__)

            if conv is not None:
                try:
                    self.conv = getattr(getattr(globals()['convection_schemes'], conv), conv)
                except:
                    raise Exception("Convection scheme \'"+conv+"\' specified. Valid options for convection schemes are:", convection_schemes.__all__)

        def select_initial_conditions(self, T:float=None, mdot:float=None):
            """Initialises temperature and massflow fields"""
            if T is not None:
                self.T = np.tile(T,(np.append(self.n_other,self.domain.shape)))
                self.h = self.fcns.h(self.T)
            if mdot is not None:
                self.mdot = np.tile(mdot,(np.append(self.n_other,self.domain.shape)))
            self.T = self.fcns.T(self.h)
            self.rho = self.fcns.rho(self.h)
            self.cp = self.fcns.cp(self.h)
            self.k = self.fcns.k(self.h)
            self.D = np.zeros(((2,)+(self.T.shape)))
            self.F = np.zeros(((2,)+(self.T.shape)))
            self.S = np.zeros(self.T.shape)

        def select_bc(self, bc_type:str=None, parameter:str=None, position=None, value:float=None):
            """Specify boundary condition type"""
            valid_bc_types = ['fixedValue','zeroGradient']
            if bc_type not in valid_bc_types:
                raise Exception("bc_type \'"+bc_type+"\' specified. Valid options for bc_type are:", valid_bc_types)
            valid_parameters = ['T','mdot']
            if parameter not in valid_parameters:
                raise Exception("parameter \'"+parameter+"\' specified. Valid options for parameter are:", valid_parameters)
            if not position:
                raise Exception("Keyword 'position' not specified.")
            if value is None and bc_type=='fixedValue':
                raise Exception("Keyword 'value' is needed for fixedValue type bc.")
            self.bcs.append({'type': bc_type, 'parameter': parameter, 'position': position, 'value': np.array(value)})

        def select_source_term(self, **kwargs):
            valid_source_types = ['thermal_resistance']
            if kwargs['source_type'] not in valid_source_types:
                raise Exception("source_type \'"+kwargs['source_type']+"\' specified. Valid options for source_type are:", valid_source_types)
            if kwargs['source_type'] == 'thermal_resistance':
                required = ['R','T_inf', 'position']
                for var in required:
                    if not var in kwargs:
                        raise Exception("Keyword \'"+var+"\' not specified for source of type \'"+kwargs['source_type']+"\'")
            self.sources.append(kwargs)

        def select_output(self, times:list[float]=None, parameters:list[str]=None):
            class Data(object):
                pass
            self.data = Data()
            self.data.time = np.array(times)
            self.data.parameters = parameters
            for parameter in parameters:
                setattr(self.data,parameter,np.zeros((len(times), self.n_other, self.n)))
                self._flag_save_data = True
                self._q = 0

        def _save_data(self, t:float=None):
            if self._flag_save_data:
                if t in self.data.time:
                    self.data.time[self._q] = t
                    for parameter in self.data.parameters: 
                        getattr(self.data,parameter)[self._q] = getattr(self,parameter)
                        self._q = self._q+1

        def _create_plot(self, sim_name:str=None):
            for parameter in self.data.parameters:
                filename='ot_plot_'+sim_name+'_'+datetime.datetime.now().strftime("%Y-%m-%d_%H%M")+'_'+self.type+'_'+parameter+'.png'
                fig, ax = plt.subplots()
                fig.tight_layout(pad=2)

                ax.plot(self.domain.node_pos, np.mean(getattr(self.data,parameter),1).transpose())
                plt.grid()
                plt.xlabel('Position (m)')
                plt.ylabel('$%s_{%s}$' % (parameter, self.type))
                #plt.legend(['$\it{t}$ = '+str(s)+' s' for s in getattr(self.data,'time')], loc='lower right')
                plt.legend(['$\it{t}$ = '+str(s)+' s' for s in getattr(self.data,'time')], bbox_to_anchor=(0, 1), loc='outside left', ncol=3)
                #plt.legend( bbox_to_anchor=(0, -0.15, 1, 0), loc=2, ncol=2, mode="expand", borderaxespad=0)
                plt.savefig(filename)

        def _create_animation(self, sim_name:str=None):
            def _update(frame):

                x = self.domain.node_pos
                y = np.mean(getattr(self.data,parameter),1)[frame]

                ax.clear()
                ax.set_xlabel('Position (m)')
                ax.set_ylabel('Temperature (C)')
                ax.set_xlim(np.min(self.domain.node_pos), np.max(self.domain.node_pos))
                ax.set_ylim(np.min(getattr(self.data,parameter)-273.15), np.max(getattr(self.data,parameter)-273.15))
                ax.grid()
                ax.text(.05, .95, 'Simulated with OpenTerrace', ha='left', va='top', transform=ax.transAxes, color = '#4cae4f',
                    bbox=dict(facecolor='white',boxstyle="square,pad=0.5", alpha=0.5))

                ax.plot(x, y.T-273.15, color = '#4cae4f')
                ax.set_title('Time: ' + str(np.round(self.data.time[frame], decimals=2)) + ' s')

            for parameter in self.data.parameters:
                fig, ax = plt.subplots()
                fig.tight_layout(pad=2)

                filename='ot_ani_'+sim_name+'_'+datetime.datetime.now().strftime("%Y-%m-%d_%H%M")+'_'+self.type+'_'+parameter+'.gif'

                ani = anim.FuncAnimation(fig, _update, frames=np.arange(len(getattr(self.data,parameter))))
                ani.save(filename, writer=anim.PillowWriter(fps=5),progress_callback=lambda i, n: print(f'{self.type}: saving animation frame {i}/{n}'))

        def _update_properties(self):
            """Updates properties based on specific enthalpy"""
            self.T = self.fcns.T(self.h)
            self.rho = self.fcns.rho(self.h)
            self.cp = self.fcns.cp(self.h)

            if hasattr(self, 'diff'):
                self.k = self.fcns.k(self.h)
                self.D[0,:,:] = self.k*self.domain.A[0]/self.domain.dx
                self.D[1,:,:] = self.k*self.domain.A[1]/self.domain.dx

            if hasattr(self, 'conv'):
                self.F[0,:,:] = self.mdot*self.cp
                self.F[1,:,:] = self.mdot*self.cp

        def _update_boundary_nodes(self, t:float=None, dt:float=None):
            """Update boundary nodes"""
            for bc in self.bcs:
                if bc['type'] == 'fixedValue':
                    self.h[bc['position']] = self.fcns.h(bc['value'])
                if bc['type'] == 'fixedValue_timevarying':
                    self.h[bc['position']] = self.fcns.h(np.interp(t,bc['value'][:,0],bc['value'][:,1]))
                if bc['type'] == 'zeroGradient':
                    if bc['position'] == np.s_[:,0]:
                        self.h[bc['position']] = self.h[bc['position']] + (2*self.T[:,1]*self.D[1,:,0] - 2*self.T[:,0]*self.D[1,:,0] - self.F[0,:,1]*self.T[:,1] + self.F[1,:,0]*self.T[:,0]) / (self.rho[:,0]*self.domain.V[0])*dt
                    if bc['position'] == np.s_[:,-1]:
                        self.h[bc['position']] = self.h[bc['position']] + (2*self.T[:,-2]*self.D[0,:,-1] - 2*self.T[:,-1]*self.D[0,:,-1] + self.F[1,:,-2]*self.T[:,-2] - self.F[0,:,-1]*self.T[:,-1]) / (self.rho[:,-1]*self.domain.V[-1])*dt

        def _update_source(self, dt:float=None):
            for source in self.sources:
                if source['source_type'] == 'thermal_resistance':
                    self.h[source['position']] = self.h[source['position']] + (2/source['R'] * (source['T_inf']-self.T[source['position']])) / (self.rho[source['position']]*self.domain.V[source['position'][1]])*dt

        def _solve_equations(self, t:float=None, dt:float=None):
            self._update_boundary_nodes(t, dt)
            if hasattr(self, 'diff'):
                self.h = self.h + self.diff(self.T, self.D)/(self.rho*self.domain.V)*dt
            if hasattr(self, 'conv'):
                self.h = self.h + self.conv(self.T, self.F)/(self.rho*self.domain.V)*dt
            if self.sources is not None:
                self._update_source(dt)

    def select_coupling(self, fluid_phase:int=None, bed_phase:int=None, h_exp:str=None, h_value:float=None):
        valid_h_exp = ['constant']
        if h_exp not in valid_h_exp:
            raise Exception("h_exp \'"+h_exp+"\' specified. Valid options for h_exp are:", valid_h_exp)

        self.coupling.append({"fluid_phase":fluid_phase, "bed_phase":bed_phase, "h_exp":h_exp, "h_value":h_value})
        self.flag_coupling = True

    def _coupling(self):
        for couple in self.coupling:
            Q = couple['h_value']*self.Phase.instances[couple['bed_phase']].domain.A[-1][-1]*(self.Phase.instances[couple['fluid_phase']].T[0]-self.Phase.instances[couple['bed_phase']].T[:,-1])*self.dt
            self.Phase.instances[couple['bed_phase']].h[:,-1] = self.Phase.instances[couple['bed_phase']].h[:,-1] + Q/(self.Phase.instances[couple['bed_phase']].rho[:,-1] * self.Phase.instances[couple['bed_phase']].domain.V[-1])
            self.Phase.instances[couple['fluid_phase']].h[0] = self.Phase.instances[couple['fluid_phase']].h[0] - (1-self.Phase.instances[couple['fluid_phase']].phi)*(self.Phase.instances[couple['fluid_phase']].domain.V * self.Phase.instances[couple['fluid_phase']].phi) / np.sum(self.Phase.instances[couple['bed_phase']].domain.V) * Q/(self.Phase.instances[couple['fluid_phase']].rho*self.Phase.instances[couple['fluid_phase']].domain.V)

    def run_simulation(self):
        """This is the function full of magic."""
        for t in tqdm.tqdm(np.arange(self.t_start, self.t_end+self.dt, self.dt)):
            for phase_instance in self.Phase.instances:
                phase_instance._solve_equations(t, self.dt)
                phase_instance._update_properties()
                phase_instance._save_data(t)
            if self.flag_coupling:
                self._coupling()

    def generate_plots(self):
        for phase_instance in self.Phase.instances:
            if phase_instance._flag_save_data:
                phase_instance._create_plot(self.sim_name)

    def generate_animations(self):
        for phase_instance in self.Phase.instances:
            if phase_instance._flag_save_data:
                phase_instance._create_animation(self.sim_name)
Phase
Source code in openterrace/openterrace.py 
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class Phase:
    instances = []
    """Main class to define either the fluid or bed phase."""
    def __init__(self, n:int=None, n_other:int=1, type:str=None):
        """Initialise a phase with number of control points and type.

        Args:
            n_self (int): Number of discretisations for the given phase
            n_other (int): Number of discretisations for the other phase
            type (str): Type of phase
        """
        self.__class__.instances.append(self)
        self.n = n
        self.n_other = n_other

        self.phi = 1

        self.bcs = []
        self.sources = []

        self._flag_save_data = False

        self.type = type
        self._valid_inputs(type)

    def _valid_inputs(self, type:str=None):
        """Gets valid domain and substances depending on type of phase.
        """
        self.valid_domains = globals()['domains'].__all__
        self.valid_substances = globals()[type+'_substances'].__all__

    def select_substance_on_the_fly(self, cp:float=None, rho:float=None, k:float=None):
        """Defines and selects a new substance on-the-fly. This is useful for defining a substance for testing purposes with temperature independent properties.

        Args:
            cp (float): Specific heat capacity in J/(kg K)
            rho (float): Density in kg/m^3
            k (float): Thermal conductivity in W/(m K)
        """
        class dummy:
            pass
        self.fcns = dummy()
        self.fcns.h = lambda T: np.ones_like(T)*T*cp
        self.fcns.T = lambda h: np.ones_like(h)*h/cp
        self.fcns.cp = lambda h: np.ones_like(h)*cp
        self.fcns.k = lambda h: np.ones_like(h)*k
        self.fcns.rho = lambda h: np.ones_like(h)*rho

    def select_substance(self, substance:str=None):
        """Selects one of the predefined substancers.

        Args:
            substance (str): Substance name
        """
        if not substance:
            raise Exception("Keyword 'substance' not specified.")
        if not substance in self.valid_substances:
            raise Exception(substance+" specified as "+self.type+" substance. Valid "+self.type+" substances are:", self.valid_substances)
        self.fcns = getattr(globals()[self.type+'_substances'], substance)

    def select_domain_shape(self, domain:str=None, **kwargs):
        """Select domain shape and initialise constants."""
        kwargs['n'] = self.n
        if not domain:
            raise Exception("Keyword 'domain' not specified.")
        if not domain in globals()['domains'].__all__:
            raise Exception("domain \'"+domain+"\' specified. Valid options for domain are:", self.valid_domains)
        self.domain = getattr(globals()['domains'], domain)
        self.domain.type = domain
        self.domain.validate_input(kwargs, domain)
        self.domain.shape = self.domain.shape(kwargs)
        self.domain.node_pos = self.domain.node_pos(kwargs)
        self.domain.dx = self.domain.dx(kwargs)
        self.domain.A = self.domain.A(kwargs)
        self.domain.V = self.domain.V(kwargs)

    def select_porosity(self, phi:float=1):
        """Select porosity from 0 to 1, e.g. filling the domain with the phase up to a certain degree."""
        self.domain.V = self.domain.V*phi
        self.phi = phi

    def select_schemes(self, diff:str=None, conv:str=None):
        """Imports the specified diffusion and convection schemes."""

        if self.domain.type == 'lumped':
            raise Exception("'lumped' has been selected as domain type. Please don't specify a discretisation scheme.")

        if diff is not None:
            try:
                self.diff = getattr(getattr(globals()['diffusion_schemes'], diff), diff)
            except:
                raise Exception("Diffusion scheme \'"+diff+"\' specified. Valid options for diffusion schemes are:", diffusion_schemes.__all__)

        if conv is not None:
            try:
                self.conv = getattr(getattr(globals()['convection_schemes'], conv), conv)
            except:
                raise Exception("Convection scheme \'"+conv+"\' specified. Valid options for convection schemes are:", convection_schemes.__all__)

    def select_initial_conditions(self, T:float=None, mdot:float=None):
        """Initialises temperature and massflow fields"""
        if T is not None:
            self.T = np.tile(T,(np.append(self.n_other,self.domain.shape)))
            self.h = self.fcns.h(self.T)
        if mdot is not None:
            self.mdot = np.tile(mdot,(np.append(self.n_other,self.domain.shape)))
        self.T = self.fcns.T(self.h)
        self.rho = self.fcns.rho(self.h)
        self.cp = self.fcns.cp(self.h)
        self.k = self.fcns.k(self.h)
        self.D = np.zeros(((2,)+(self.T.shape)))
        self.F = np.zeros(((2,)+(self.T.shape)))
        self.S = np.zeros(self.T.shape)

    def select_bc(self, bc_type:str=None, parameter:str=None, position=None, value:float=None):
        """Specify boundary condition type"""
        valid_bc_types = ['fixedValue','zeroGradient']
        if bc_type not in valid_bc_types:
            raise Exception("bc_type \'"+bc_type+"\' specified. Valid options for bc_type are:", valid_bc_types)
        valid_parameters = ['T','mdot']
        if parameter not in valid_parameters:
            raise Exception("parameter \'"+parameter+"\' specified. Valid options for parameter are:", valid_parameters)
        if not position:
            raise Exception("Keyword 'position' not specified.")
        if value is None and bc_type=='fixedValue':
            raise Exception("Keyword 'value' is needed for fixedValue type bc.")
        self.bcs.append({'type': bc_type, 'parameter': parameter, 'position': position, 'value': np.array(value)})

    def select_source_term(self, **kwargs):
        valid_source_types = ['thermal_resistance']
        if kwargs['source_type'] not in valid_source_types:
            raise Exception("source_type \'"+kwargs['source_type']+"\' specified. Valid options for source_type are:", valid_source_types)
        if kwargs['source_type'] == 'thermal_resistance':
            required = ['R','T_inf', 'position']
            for var in required:
                if not var in kwargs:
                    raise Exception("Keyword \'"+var+"\' not specified for source of type \'"+kwargs['source_type']+"\'")
        self.sources.append(kwargs)

    def select_output(self, times:list[float]=None, parameters:list[str]=None):
        class Data(object):
            pass
        self.data = Data()
        self.data.time = np.array(times)
        self.data.parameters = parameters
        for parameter in parameters:
            setattr(self.data,parameter,np.zeros((len(times), self.n_other, self.n)))
            self._flag_save_data = True
            self._q = 0

    def _save_data(self, t:float=None):
        if self._flag_save_data:
            if t in self.data.time:
                self.data.time[self._q] = t
                for parameter in self.data.parameters: 
                    getattr(self.data,parameter)[self._q] = getattr(self,parameter)
                    self._q = self._q+1

    def _create_plot(self, sim_name:str=None):
        for parameter in self.data.parameters:
            filename='ot_plot_'+sim_name+'_'+datetime.datetime.now().strftime("%Y-%m-%d_%H%M")+'_'+self.type+'_'+parameter+'.png'
            fig, ax = plt.subplots()
            fig.tight_layout(pad=2)

            ax.plot(self.domain.node_pos, np.mean(getattr(self.data,parameter),1).transpose())
            plt.grid()
            plt.xlabel('Position (m)')
            plt.ylabel('$%s_{%s}$' % (parameter, self.type))
            #plt.legend(['$\it{t}$ = '+str(s)+' s' for s in getattr(self.data,'time')], loc='lower right')
            plt.legend(['$\it{t}$ = '+str(s)+' s' for s in getattr(self.data,'time')], bbox_to_anchor=(0, 1), loc='outside left', ncol=3)
            #plt.legend( bbox_to_anchor=(0, -0.15, 1, 0), loc=2, ncol=2, mode="expand", borderaxespad=0)
            plt.savefig(filename)

    def _create_animation(self, sim_name:str=None):
        def _update(frame):

            x = self.domain.node_pos
            y = np.mean(getattr(self.data,parameter),1)[frame]

            ax.clear()
            ax.set_xlabel('Position (m)')
            ax.set_ylabel('Temperature (C)')
            ax.set_xlim(np.min(self.domain.node_pos), np.max(self.domain.node_pos))
            ax.set_ylim(np.min(getattr(self.data,parameter)-273.15), np.max(getattr(self.data,parameter)-273.15))
            ax.grid()
            ax.text(.05, .95, 'Simulated with OpenTerrace', ha='left', va='top', transform=ax.transAxes, color = '#4cae4f',
                bbox=dict(facecolor='white',boxstyle="square,pad=0.5", alpha=0.5))

            ax.plot(x, y.T-273.15, color = '#4cae4f')
            ax.set_title('Time: ' + str(np.round(self.data.time[frame], decimals=2)) + ' s')

        for parameter in self.data.parameters:
            fig, ax = plt.subplots()
            fig.tight_layout(pad=2)

            filename='ot_ani_'+sim_name+'_'+datetime.datetime.now().strftime("%Y-%m-%d_%H%M")+'_'+self.type+'_'+parameter+'.gif'

            ani = anim.FuncAnimation(fig, _update, frames=np.arange(len(getattr(self.data,parameter))))
            ani.save(filename, writer=anim.PillowWriter(fps=5),progress_callback=lambda i, n: print(f'{self.type}: saving animation frame {i}/{n}'))

    def _update_properties(self):
        """Updates properties based on specific enthalpy"""
        self.T = self.fcns.T(self.h)
        self.rho = self.fcns.rho(self.h)
        self.cp = self.fcns.cp(self.h)

        if hasattr(self, 'diff'):
            self.k = self.fcns.k(self.h)
            self.D[0,:,:] = self.k*self.domain.A[0]/self.domain.dx
            self.D[1,:,:] = self.k*self.domain.A[1]/self.domain.dx

        if hasattr(self, 'conv'):
            self.F[0,:,:] = self.mdot*self.cp
            self.F[1,:,:] = self.mdot*self.cp

    def _update_boundary_nodes(self, t:float=None, dt:float=None):
        """Update boundary nodes"""
        for bc in self.bcs:
            if bc['type'] == 'fixedValue':
                self.h[bc['position']] = self.fcns.h(bc['value'])
            if bc['type'] == 'fixedValue_timevarying':
                self.h[bc['position']] = self.fcns.h(np.interp(t,bc['value'][:,0],bc['value'][:,1]))
            if bc['type'] == 'zeroGradient':
                if bc['position'] == np.s_[:,0]:
                    self.h[bc['position']] = self.h[bc['position']] + (2*self.T[:,1]*self.D[1,:,0] - 2*self.T[:,0]*self.D[1,:,0] - self.F[0,:,1]*self.T[:,1] + self.F[1,:,0]*self.T[:,0]) / (self.rho[:,0]*self.domain.V[0])*dt
                if bc['position'] == np.s_[:,-1]:
                    self.h[bc['position']] = self.h[bc['position']] + (2*self.T[:,-2]*self.D[0,:,-1] - 2*self.T[:,-1]*self.D[0,:,-1] + self.F[1,:,-2]*self.T[:,-2] - self.F[0,:,-1]*self.T[:,-1]) / (self.rho[:,-1]*self.domain.V[-1])*dt

    def _update_source(self, dt:float=None):
        for source in self.sources:
            if source['source_type'] == 'thermal_resistance':
                self.h[source['position']] = self.h[source['position']] + (2/source['R'] * (source['T_inf']-self.T[source['position']])) / (self.rho[source['position']]*self.domain.V[source['position'][1]])*dt

    def _solve_equations(self, t:float=None, dt:float=None):
        self._update_boundary_nodes(t, dt)
        if hasattr(self, 'diff'):
            self.h = self.h + self.diff(self.T, self.D)/(self.rho*self.domain.V)*dt
        if hasattr(self, 'conv'):
            self.h = self.h + self.conv(self.T, self.F)/(self.rho*self.domain.V)*dt
        if self.sources is not None:
            self._update_source(dt)
instances = [] class-attribute instance-attribute

Main class to define either the fluid or bed phase.

__init__(n=None, n_other=1, type=None)

Initialise a phase with number of control points and type.

Parameters:

Name Type Description Default
n_self int

Number of discretisations for the given phase

 required
n_other int

Number of discretisations for the other phase

 1
type str

Type of phase

 None
Source code in openterrace/openterrace.py 
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def __init__(self, n:int=None, n_other:int=1, type:str=None):
    """Initialise a phase with number of control points and type.

    Args:
        n_self (int): Number of discretisations for the given phase
        n_other (int): Number of discretisations for the other phase
        type (str): Type of phase
    """
    self.__class__.instances.append(self)
    self.n = n
    self.n_other = n_other

    self.phi = 1

    self.bcs = []
    self.sources = []

    self._flag_save_data = False

    self.type = type
    self._valid_inputs(type)
select_bc(bc_type=None, parameter=None, position=None, value=None)

Specify boundary condition type

Source code in openterrace/openterrace.py 
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def select_bc(self, bc_type:str=None, parameter:str=None, position=None, value:float=None):
    """Specify boundary condition type"""
    valid_bc_types = ['fixedValue','zeroGradient']
    if bc_type not in valid_bc_types:
        raise Exception("bc_type \'"+bc_type+"\' specified. Valid options for bc_type are:", valid_bc_types)
    valid_parameters = ['T','mdot']
    if parameter not in valid_parameters:
        raise Exception("parameter \'"+parameter+"\' specified. Valid options for parameter are:", valid_parameters)
    if not position:
        raise Exception("Keyword 'position' not specified.")
    if value is None and bc_type=='fixedValue':
        raise Exception("Keyword 'value' is needed for fixedValue type bc.")
    self.bcs.append({'type': bc_type, 'parameter': parameter, 'position': position, 'value': np.array(value)})
select_domain_shape(domain=None, **kwargs)

Select domain shape and initialise constants.

Source code in openterrace/openterrace.py 
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def select_domain_shape(self, domain:str=None, **kwargs):
    """Select domain shape and initialise constants."""
    kwargs['n'] = self.n
    if not domain:
        raise Exception("Keyword 'domain' not specified.")
    if not domain in globals()['domains'].__all__:
        raise Exception("domain \'"+domain+"\' specified. Valid options for domain are:", self.valid_domains)
    self.domain = getattr(globals()['domains'], domain)
    self.domain.type = domain
    self.domain.validate_input(kwargs, domain)
    self.domain.shape = self.domain.shape(kwargs)
    self.domain.node_pos = self.domain.node_pos(kwargs)
    self.domain.dx = self.domain.dx(kwargs)
    self.domain.A = self.domain.A(kwargs)
    self.domain.V = self.domain.V(kwargs)
select_initial_conditions(T=None, mdot=None)

Initialises temperature and massflow fields

Source code in openterrace/openterrace.py 
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def select_initial_conditions(self, T:float=None, mdot:float=None):
    """Initialises temperature and massflow fields"""
    if T is not None:
        self.T = np.tile(T,(np.append(self.n_other,self.domain.shape)))
        self.h = self.fcns.h(self.T)
    if mdot is not None:
        self.mdot = np.tile(mdot,(np.append(self.n_other,self.domain.shape)))
    self.T = self.fcns.T(self.h)
    self.rho = self.fcns.rho(self.h)
    self.cp = self.fcns.cp(self.h)
    self.k = self.fcns.k(self.h)
    self.D = np.zeros(((2,)+(self.T.shape)))
    self.F = np.zeros(((2,)+(self.T.shape)))
    self.S = np.zeros(self.T.shape)
select_porosity(phi=1)

Select porosity from 0 to 1, e.g. filling the domain with the phase up to a certain degree.

Source code in openterrace/openterrace.py 
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def select_porosity(self, phi:float=1):
    """Select porosity from 0 to 1, e.g. filling the domain with the phase up to a certain degree."""
    self.domain.V = self.domain.V*phi
    self.phi = phi
select_schemes(diff=None, conv=None)

Imports the specified diffusion and convection schemes.

Source code in openterrace/openterrace.py 
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def select_schemes(self, diff:str=None, conv:str=None):
    """Imports the specified diffusion and convection schemes."""

    if self.domain.type == 'lumped':
        raise Exception("'lumped' has been selected as domain type. Please don't specify a discretisation scheme.")

    if diff is not None:
        try:
            self.diff = getattr(getattr(globals()['diffusion_schemes'], diff), diff)
        except:
            raise Exception("Diffusion scheme \'"+diff+"\' specified. Valid options for diffusion schemes are:", diffusion_schemes.__all__)

    if conv is not None:
        try:
            self.conv = getattr(getattr(globals()['convection_schemes'], conv), conv)
        except:
            raise Exception("Convection scheme \'"+conv+"\' specified. Valid options for convection schemes are:", convection_schemes.__all__)
select_substance(substance=None)

Selects one of the predefined substancers.

Parameters:

Name Type Description Default
substance str

Substance name

 None
Source code in openterrace/openterrace.py 
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def select_substance(self, substance:str=None):
    """Selects one of the predefined substancers.

    Args:
        substance (str): Substance name
    """
    if not substance:
        raise Exception("Keyword 'substance' not specified.")
    if not substance in self.valid_substances:
        raise Exception(substance+" specified as "+self.type+" substance. Valid "+self.type+" substances are:", self.valid_substances)
    self.fcns = getattr(globals()[self.type+'_substances'], substance)
select_substance_on_the_fly(cp=None, rho=None, k=None)

Defines and selects a new substance on-the-fly. This is useful for defining a substance for testing purposes with temperature independent properties.

Parameters:

Name Type Description Default
cp float

Specific heat capacity in J/(kg K)

 None
rho float

Density in kg/m^3

 None
k float

Thermal conductivity in W/(m K)

 None
Source code in openterrace/openterrace.py 
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def select_substance_on_the_fly(self, cp:float=None, rho:float=None, k:float=None):
    """Defines and selects a new substance on-the-fly. This is useful for defining a substance for testing purposes with temperature independent properties.

    Args:
        cp (float): Specific heat capacity in J/(kg K)
        rho (float): Density in kg/m^3
        k (float): Thermal conductivity in W/(m K)
    """
    class dummy:
        pass
    self.fcns = dummy()
    self.fcns.h = lambda T: np.ones_like(T)*T*cp
    self.fcns.T = lambda h: np.ones_like(h)*h/cp
    self.fcns.cp = lambda h: np.ones_like(h)*cp
    self.fcns.k = lambda h: np.ones_like(h)*k
    self.fcns.rho = lambda h: np.ones_like(h)*rho
__init__(t_end=None, dt=None, sim_name=None)

Initialise with various control parameters.

Parameters:

Name Type Description Default
t_end float

End time in s

 None
dt float

Time step size in s

 None
Source code in openterrace/openterrace.py 
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def __init__(self, t_end:float=None, dt:float=None, sim_name:str=None):
    """Initialise with various control parameters.

    Args:
        t_end (float): End time in s
        dt (float): Time step size in s
    """
    self.t_start = 0
    self.t_end = t_end
    self.dt = dt
    self.coupling = []
    self.flag_coupling = False
    self.sim_name = sim_name
run_simulation()

This is the function full of magic.

Source code in openterrace/openterrace.py 
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def run_simulation(self):
    """This is the function full of magic."""
    for t in tqdm.tqdm(np.arange(self.t_start, self.t_end+self.dt, self.dt)):
        for phase_instance in self.Phase.instances:
            phase_instance._solve_equations(t, self.dt)
            phase_instance._update_properties()
            phase_instance._save_data(t)
        if self.flag_coupling:
            self._coupling()