An Experimental Study of a Type of Vortex Sink Rate Sensors

In order to study the flow field in the sink region of a vortex Sink Rate Sensor, an experimental study was initiated .. Using two probes, one for the total pressure measurements and the other for the static pressure measurements, data was collected for two flow rates, various rates of rotation and at various points in the sink region of the flow. For the sensor (coupler inside diameter 5.0 inches and height 0.50 inches) with slenderness parameter of unity, four important conclusions were drawn from the data. At a given location in the flow field the magnitude of the tangential component of velocity increased for decreased flow rates. Viscous core did exist in the sink flow and outside of it the tangential component of velocity was negligibly small Within the viscous core the tangential component of velocity increased in a general manner with increased rates of rotation. The maximum of the tangential component of velocity occurred within the entrance region to the sink tube.