A NUMERICAL STUDY FOR THE PREDICTION OF TURBULENT MIXING FACTOR IN THERMAL STORAGE TANKS

The transient behavior of thermal stratification in storage systems we re investigated numerically. An efficient computer code based on Chape au-Galerkin integral formulation is developed. The validation of the p resent scheme is verified against published experimental and finite di fference results. The predictions are adequately simulate the publishe d data. The present results showed that the turbulent mixing (or eddy conductivity) factor caused by hydrodynamic disturbances at the inlet and outlet ports of storage tank plays an important role in the perfor mance of thermal stratification storage tanks. The eddy conductivity f actor is included in the model to yield good agreement with experiment al data. Further, the variation of this factor is expressed in a decre asing exponential function in terms of Reynolds and Richardson numbers . The effect of nodal grid size on the computed results is also invest igated. It is found to have negligible effect on the temperature profi les al moderate grid size. (C) 1997 Published by Elsevier Science Ltd.