Laboratory simulation of heat transfer in liquids with Pr > 1. Temperature field

Abstract

Combined measurements of heat transfer coefficients, average temperature profiles, and statistical characteristics of temperature fluctuations were performed for a water flow in a round heated pipe on a laboratory test installation. The studies were carried out with reference to physical simulation of heat transfer in molten salts, which are promising heat tranport media in nuclear and thermonuclear power engineering. The use of original probes with microthermocouples allowed one to perform measurements in many cross-sections along the length of the heated pipe with a small step in radial direction from the axis to the touch point between the probe and the wall in each cross-section. Detailed temperature measurements were performed in near wall region witin the viscous sublayer. This information is especially important for liquids with Prandtl numbers Pr > 1, such as water and molten salts. The tendencies in stabilization of the local heat transfer coefficients, average temperature fields, and temperature fluctuation intensity were investigated. The data presented here are useful for optimization and verification of numerical simulation codes for heat transfer of liquids with large Prandtl numbers.