Tube-Side Heat Transfer and Pressure Drop for Tubes Having Helical Internal Ridging with Turbulent/Transitional Flow of Single-Phase Fluid. Part 2. Multiple-Helix Ridging

An experimental investigation was conducted of the tube-side behavior of various internal configurations with turbulent/transitional flow of water in the Reynolds number range 10,000-120,000 and Prandtl number range 4-10. By using a heat-momentum transfer analogy, correlations were obtained that enable practical designs with standard products or optimization of tube geometry for specific conditions. The previous article in this two-part series dealt with single-helix internal ridged tubes. This part gives the results for tubes having multiple-helix ridging.