Dear All,

For a fluid flow (with very high viscosity) in a pipe, how to estimate the entrance length? the Re number is less than 1. It seems that the entrance length is significantly long since the temperature increase I got from commercial software doesn't follow the fully developed region equation.

Thanks in advance.

snowshovel

You may find correlations for the entrance length in pipe flow in most textbooks (e.g., Ozisik, Heat Transfer - A Basic Aprrocah, 1985, Table 7-2).