2-D Thermal Velocity Sensor for Submersible Navigation and Minute Flow Measurements

A 2-D thermal velocity microsensor for use as a navigational aid and for flow measurements on a miniaturized submersible is developed in this paper. The sensor with nickel heater and temperature sensors on a Pyrex substrate, designed for mounting on the outside of the submersible hull, is fabricated and tested in an application-like environment and proven to be able to measure water speed from zero to 40 mm/s with a power consumption less than 15 mW and determine the flow direction with an error less than ±8
^°
. Finite Element Analysis is used to investigate design and operation parameters and possible biofouling effects on the sensor signal. The effect on shape and orientation of the sensor's mounting surface is also studied.