Layout of a Fluid Flow Experiment

An experimental setup consists of certain essential elements which enable the measurement of physical quantities such as velocity, pressure and temperature at distinct locations in the flow domain. The physical domain is a fluid region in which velocity, pressure and temperature fields are present. The fields vary in general from point to point and with time. A probe is located in the flow and its state is altered corresponding to changes in the flow quantity to be measured. In principle the probe does not affect the flow itself. The measurement system senses the altered state of the probe and generates a signal that can be understood by the observer. Alternatively, it produces an electrical signal, which can be amplified, filtered and digitized by a signal analyzer. This signal can be conveniently displayed on an output device such as voltmeter or stored in a computer for data processing. Usually the observer receives the output of a probe as an electrical voltage generated by the measurement system. When the output of the probe is an electrical signal it is called a transducer.