Читать книгу Vibroacoustic Simulation - Alexander Peiffer - Страница 73

In the considerations in this chapter so far, we neglected the source terms related to the conservation of mass and momentum. All sources discussed until now are caused by vibrating surfaces. For establishing a physical link between the source term and the specific mass flow q˙s in Equation (2.3) and force density term f in Equation (2.8) we keep the terms this time. The source terms are not influenced by the linearization procedure; thus, the inhomogeneous and linear equations of momentum (2.24) and continuity (2.23) read as

(2.121)

Repeating the steps of section 2.2.5 we finally get the inhomogeneous wave equation

(2.122)

The density source is converted into a volume source strength density by ρ˙s=ρ0qs(t). The above equation can also be converted into the frequency domain and hence to the inhomogeneous Helmholtz equation

(2.123)