ENHANCEMENT OF HEAT-TRANSFER IN SQUARE HELICAL DUCTS

A three-dimensional numerical investigation of steady laminar flow and heat transfer is undertaken to determine the developing as well as fu lly developed temperature fields. Physical interpretation is given for the enhancement of the heat transfer coefficient at the thermal entra nce region and the overall increase in heat transfer in helical ducts compared to straight ducts. The variation of peripherally averaged Nus selt number is studied for the constant wall temperature boundary cond ition. Detailed analysis is given for the peripheral variation of Nuss elt number and the temperature field at different cross-sectional plan es. The effect of the Prandtl number on the temperature field is also studied. The problem is solved using a segregated solution approach wh ich reduces the total computer memory requirements.