Hello,
I'm currently performing simulations of a spherical mono element transducer radiating in a multilayered axisymmetric domain. My goal is to evaluate temperature elevations produced by this transducer in the presence of those layers. The input of these simulations is the total acoustic power emitted by the transducer measured in water using a radiation force balance.
To be able to run the simulation I have to go from this acoustic power tx_emitted_ac_power to pressure magnitudes tx_p_mag that can be applied to the transducer surface.
Considering the plane wave assumption, a pressure magnitude can be obtained such that
tx_p_mag = sqrt(2) * sqrt((tx_emitted_ac_power * rho_tx_coupling_medium * c_tx_coupling_medium) / tx_surface_area).
Regarding the transducer surface, my first instinct was to evaluate it as a section of a sphere such that
tx_surface_area = 2pi * r (r- sqrt(r^2 - a^2)) where r corresponds to the radius of curvature and a to half of the transducer aperture.
After several validation with Rayleigh-based simulation models in homogeneous domains, I realized that the pressures obtained with kWave were consistently under-estimated.
I later realized that evaluating tx_surface_area as the planar projection of the transducer aperture tx_surface_area = pi * (tx_aperture / 2)^2 led to an agreement of kWave with the reference Rayleigh simulations.
Does anyone know what is going on here?
Best,
Tom