Linear Wind Tunnel

The INTA facility consists of a 500 mm diameter tunnel, six meters long, that moves the test
bench  at  variable speeds under different ambient conditions. The test bench consists of a pan and tilt unit that can move the sample 90º in pitch and 180º in yaw. The following test  conditions are able to be reproduced:

They are four pressure sensors that control the pressure in the chamber. Three  were chosen due to its good working range between 3 and 12 mbars which is Mars pressure range, the fourth one measure between 100mbar and ambient. The dual gage pressure logger shows the pressure  in a digital display so we are able to have a real time pressure reading. The error  reading is 0.01 mbar.

A DC motor& control moves the linear guide in a low friction constant velocity movement. The control box is linked to a computer application that will enable us to record all parameters like temperature and pressure inside the tunnel and vary and record velocity and position of the calibration unit in the linear guide.

Through the six meters of length a pressure and temperature gauge is locates every two meters in order to see variations inside the tunnel. A second temperature sensor will be position in the moving pan and tilt and will be position as close to the real test sensor as possible.

The aim of this test is to calibrate the Calibration model(CM) of the Wind Sensor (WS) and Air Temperature Sensor (ATS). The functional test facility is a  pressurized vessel called Linear Tunnel facility. The aim of this tests are to verify that the wind and temperature sensors  are sensible to different wind speeds and directions at Mars ambient conditions in the linear tunnel facility located in INTA.

The linear wind tunnel facility is 6 meters long and we will record readings every second. For higher speeds we can work  by keeping equal Reynolds number.

For an equivalent Reynolds number we can vary density and velocity

Re= (r*V*L) / n

At equal temperatures and same test item: Re1=P1*V1

P1*V1= P2*V2