f 60[kHz] Frequency
phi (-pi/6)[rad] Wave direction angle, phi
theta (4*pi/6)[rad] Wave direction angle, theta
k1 sin(theta)*cos(phi) Incident wave direction vector, X-component
k2 sin(theta)*sin(phi) Incident wave direction vector, Y-component
k3 cos(theta) Incident wave direction vector, Z-component
R 30[mm] Model domain radius