Parametric Study of Charging Inlet Diffuser Performance in Stratified Chilled Water Storage Tanks with Radial Diffusers: Part 2-Dimensional Analysis, Parametric Simulations and Simplified Model Development

A. Musser, W. P. Bahnfleth
A parametric study of the thermal performance during charging of a full-scale radial inlet diffuser in a cylindrical stratified chilled water storage tank was performed by applying factorial experimental theory to the results of simulations performed with a validated computational fluid dynamics (CFD) model. Part 1 describes the development and validation of the CFD model. Part 2 summarizes the results of the parametric study. Dimensional storage tank and inlet diffuser parameters having the
more » ... ential to influence inlet thermal performance were identified, then formed into dimensionless groups using Buckingham Pi analysis. These included the inlet Richardson number (Ri), inlet Reynolds number (Re i ), ratio of diffuser radius to tank radius (R D /R w ) and ratio of diffuser radius to diffuser inlet height (R D /h i ). Thermal performance was measured in terms of thermocline thickness and equivalent lost tank height. Sixteen simulations comprising a full 2 k factorial experiment were completed and analyzed. Parameter ranges considered were as follows: Ri from 1.0 to 11.1, Re i from 1,000 to 12,000, R D /R w from 0.2 to 0.4 and R D /h i from 5 to 10. Within these ranges, Ri, R D /R w and R D /h i were found to be of first-order significance while Re i was not. Regression models of thermal performance metrics as functions of Ri, R D /R w and R D /h i that are sufficiently simple to be useful for design were developed. These models agreed well with CFD simulations from which they were derived and with field data.
doi:10.1080/10789669.2001.10391429 fatcat:bwisp4xnmza6vi4xged4mmmlta