Simultaneous Measurement of Fluctuating Temperature and Velocity in a Combustion Field

Abstract

A velocimeter constructed is composed of detectors and analog computing circuits through which the signals from detectors are directly converted to necessary values. The detectors have a thermocouple, static-and total-pressure probes respectively connected to condenser microphones and a differential pressure meter. With this constitution this velocimeter revealed its performance to be in the same level as a hot-wire velocimeter for a flameless field and provided more accurate turbulence degree in a combustion field than the earlier methods based on the measurement of only pressure variation. Through the application for an open diffusion flame, it was shown that the time constant of thermocouple can be estimated from Nusselt's number equation by Ahmad in combination with the signals obtained, and further that the correlation between temperature and velocity fluctuations becomes negative at the inside of maximum temperature location and positive at its outside.