Velocity calibration relationships for hot-wire anemometry

Abstract

Describes a study of the accuracy and suitability of hot-wire velocity calibration relations for implementation on a micro/minicomputer. The investigation has covered simple and extended power laws, polynomial fits of three types and spline fits. The main part of the investigation was related to a typical moderate velocity range of 3-30 m s-1, with complementary data being presented for a large velocity range, 4-90 m s-1, and at low velocities, 1-6 m s-1. By careful attention to measurement errors, the suitability or limitations of the various calibration relationships have been identified. Optimisation for both accuracy and computational convenience identified no simple method as being the best, but three methods: simple power law or a fourth-order polynomial in E or a third-order polynomial in E2, were shown to give similar results.