MEMS-Based Probes for Velocity and Pressure Measurements in Unsteady and Turbulent Flowfields

摘要

This report presents our work in the development of fast-response, high-accuracy multi-sensor pressure probes of miniature size for velocity and pressure measurement in unsteady and turbulent flowfields, with emphasis on MEMS-based pressure probes. The fabrication and calibration (theoretical and experimental) of miniature (order of 1mm to 2mm in diameter) 5-sensor hemispherical-tip probes, are discussed. The first stages of the development process have been to fabricate a sensitive MEMS pressure sensor and to develop calibration algorithms and environments for fast-response probes. The work resulted in a prototype MEMS-based 5 sensor probe, several embedded-sensor, fast response 5-sensor probes, and high accuracy steady and unsteady probe calibration and data-reduction algorithms. The work has produced a new type of flow-diagnostics probes that are anticipated to prove valuable to the fluid mechanics community. They are significantly more rugged than hot-wires and much less dependent on repetitive and tedious calibration; provide much larger measurable flow angularity; and although they are not there yet, we soon expect them to be able to match or exceed a hot-wire's spatial resolution capabilities and compete with a hot-wire's frequency response.