Source code for seapy.couplings.couplingsurfaceacousticalplate

import numpy as np
from .coupling import Coupling

from . couplingsurfaceplateacoustical import radiation_efficiency, critical_frequency #CouplingSurfacePlateAcoustical

class CouplingSurfaceAcousticalPlate(Coupling):
    """
    A model describing the coupling between a cavity and a plate.
    """
    
    @property
    def impedance_from(self):
        return self.subsystem_from.impedance
    
    @property
    def impedance_to(self):
        return self.subsystem_to.impedance
    
    @property
    def critical_frequency(self):
        """
        Critical frequency
        """
        return critical_frequency(self.subsystem_to, self.subsystem_from)
    
    @property
    def critical_wavelength(self):
        """
        Wavelength belonging to critical frequency.
        
        .. math:: \\lambda_c = c_{g} / f_c
        
        """
        try:
            return self.subsystem_from.soundspeed_group / self.critical_frequency
        except FloatingPointError:
            return np.zeros(self.frequency.amount)
        
    @property
    def radiation_efficiency(self):
        """
        Radiation efficiency.
        """
        return radiation_efficiency(self, self.subsystem_to.component)
    
    #@property
    #def clf(self):
        #"""
        #Coupling loss factor for transmission from a cavity to a plate.
        
        #.. math:: \\eta_{cavity,plate} = \\frac{\\rho_0 c^2 S \\sigma f_c }{8 \\pi f^3 m^{''} V_2}
        
        #See BAC, equation 3.9
        
        #.. warning:: This one uses the consistency relation!
        
        #"""        
        #try:
            #return self.subsystem_from.component.material.density * \
                   #self.subsystem_from.soundspeed_group**2.0 *self.area * self.radiation_efficiency * \
                   #self.critical_frequency / (8.0 * np.pi * self.frequency.center**3.0 * \
                   #self.subsystem_to.component.mass_per_area * self.subsystem_from.component.volume) 
        #except (ZeroDivisionError, FloatingPointError):
            #return np.zeros(self.frequency.amount)

    @property
    def area(self):
        """
        Connecting surface.
        """
        return self.subsystem_to.component.area

    @property
    def clf(self):
        """
        Coupling loss factor for transmisson from a cavity/room to a plate/wall.
        
        .. math:: \\eta_{cavity,plate} = \\frac{5556 S_2 f_{c2} \\sigma_{2}}{V_1 \\rho{s2} f^3}
        
        See Craik, equation 1.22, page 9.
        
        """
        return 5556.0 * self.area * self.critical_frequency * self.radiation_efficiency / (self.subsystem_from.component.volume * self.subsystem_to.component.material.density * self.frequency.center**3.0)