Flow rate determination in conduits using a thermal pulse technique

Abstract

Mean speeds of laminar flow in tubes are determined non-invasively using thermocouple measurements of thermal pulse speeds. Such pulses are shown to travel at a unique submean low velocity which is directly proportional to the volume flow rate. The ratio of the thermal pulse to mean flowspeed is given by a retention factor whose value depends on only the heat capacity ratio of wall to fluid and a wall thickness parameter. Experimental results using a water-copper combination confirm these predictions over a wide velocity range.