2.5.2. Pressure and Velocity Measurement

The flow parameters pressure and velocity can be measured or derived directly with the help of measuring technology. The Prandt pitot tube (cf. Figure 2.2.2.), for example, serves as a helpful, simple measuring device. Here, only the pressure is measured and the flow velocity is calculated using the dynamic pressure formula. Further measuring equipment for the determination of the flow velocity is the hot-wire manometer, for the pressure measurement also Pitot tubes or pressure sensors can be used.

Figure 2.2.2: Flow measurements of air (gases) during flows through pipes or ducts

Dynamic pressure:   p_{\mathrm{d}}=\frac{\rho}{2} \cdot v^2

Flow rate:  v=\frac{\sqrt{2 \cdot p_{\mathrm{d}}}}{\rho}