P-2 Physical Properties of Liquids - Status of Present Knowledge and Importance in Design Methods for Heat Transfer and Fluid Flow

K. K. Nangia and J. Taborek

Heat transfer and fluid flow correlations are usually developed from experiments with simple fluids of fairly well-known physical properties. If such correlations are used for industrial design purposes, frequently involving complex mixtures, the accuracy of the results depends directly on the quality of the physical properties data and predictive correlations.

This report attempts to survey the status of the art and the availability of both data and predictive methods for transport properties of liquids. Data sources and generalized correlations are critically reviewed with special consideration being given to their importance in heat transfer and fluid flow calculations.

It is concluded that the art of physical properties prediction has not kept pace with the development of computer-based equipment design methods. Unless a serious effort to improve the situation is made, the lack of physical properties data will constitute a bottleneck in future improvements in the overall accuracy and dependability of design procedures.

The supply of physical property data to computer programs for the design of process equipment constitutes a major, time-taking chore, exposed to hard-to-detect errors of look-up, not to mention the basic inaccuracy of data proper. An urgent need exists for a physical properties estimation computer program which would be dependable and eliminate the tedious look-up work.