THE EFFECT OF HEATING ON BOUNDARY LAYER TRANSITION FOR LIQUID FLOW IN A TUBE
Abstract
The effect of heating on boundary-layer transition in a liquid was investigated. Water was circulated through a steam-heated, smooth brass tube over a range of diameter Reynolds no. from 30,000 to 140,000. For disturbance levels producing length Reynolds no. of transition up to 850,000, the extent of the laminar regime for water flowing in a pipe entry was either unaffected or slightly decreased when the pipe walls were heated. Small roughnesses on the boundary walls had a produced effect on the location of transition. The results indicate that for an ordinary water-flow system, the use of heating could not be expected to cause appreciable stabilization of the laminar boundary layer. An expression for local apparent friction factor in the laminar entry of a tube was developed by the use of an approximate boundary-layer computation method. A second solution for apparent friction factor, which applies throughout the whole laminar region of a tube, was derived by substituting an approximate velocity profile shape into the continuity and momentum equations. The velocity profile chosen approached flatplate behavior near the tube entrance, and gradually changed toward a parabolic shape as the flow developed.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jun 01, 1953
- Accession Number
- AD0017987
Entities
People
- Ascher H. Shapiro
- Robert Siegel
Organizations
- Massachusetts Institute of Technology