Steady Pressure measurements
Steady pressure measurement on the surface of the wind tunnel model is carried out to study the aerodynamic pressure and load distribution on the different components. This information is very important in structural design of the vehicle. A 0.5mm diameter hole is drilled normal to the measuring surface and is connected with a pressure-measuring device. Number of pressure ports depends upon size
of the model, location of interest and availability of pressure measuring equipments. Generally, in NTAF-NAL, multiport ESP scanners are used to measure steady pressure. In some cases, single transducers are also used. The accuracy of and ESP scanner is ±0.03 percent of the maximum pressure. The preparation of the model is a very specialized task. The connection of the port to the transducer and its mapping is done carefully by an experienced team. The pressure data is acquired at high sampling rate and is averaged to give steady data. Models with more than 300 ports and 11 scanners of 16/32 ports each have been instrumented and tested at NTAF.