ALTERNATION OF FLOW AND HEAT EXCHANGE UNDER THE CONDITIONS OF ARTIFICIAL TURBULIZATION OF FLOW IN TUBES,
Abstract
Since the results of an earlier investigation have shown that most efficient heat transfer is obtained under slight turbulization conditions, a study was made of the stability of local heat transfer in the near-critical region in tubes with turbulizers. The artificial turbulizers used were annular diaphragms of small height on the internal wall of the tube, produced by externally indenting the tube with a roller. The degree of reduction of the inside diameter of the tube diaphragms was 98.3 - 87.5%. The tube was heated with ac. The tests are briefly described. Comparison of the results with the data obtained for a smooth tube indicates that in the tube with turbulizer the temperature pulsations are produced at lower Reynolds numbers than in a smooth tube. The amplitudes of the oscillations of the wall temperature in such tubes is larger than in smooth tubes. The range of Reynolds numbers in which pulsation takes place is much smaller than in a smooth tube. The shift and decrease of the maxima of the pulsations of the characteristics on approaching the inlet to the tube is due to the character of the variation of the alternation coefficient. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Jul 23, 1968
- Accession Number
- AD0684994
Entities
People
- E. K. Kalinin
- S. A. Yarkho
Organizations
- National Air and Space Intelligence Center