Two-Phase Heat Transfer
Dr. Shah has been doing research on two-phase heat transfer for many years. He did pioneering experimental investigations on ammonia evaporators at the Technical University of Norway. This research for the first time provided observations of oil films in ammonia evaporators and provided a method to calculate their effect on heat transfer.
His major achievement has been the development of general predictive techniques for the following:
1. Heat transfer during film condensation in tubes and annuli
2. Heat transfer during saturated boiling in tubes and annuli
3. Heat transfer during sub-cooled boiling in tubes and annuli
4. Heat transfer during film boiling in tubes
5. Critical heat flux in tubes
6. Critical heat flux in annuli
7. Heat transfer during boiling with cross-flow on tubes
8. Heat transfer during pool boiling of liquid metals
9. Critical heat flux during pool boiling of liquid metals
10. Heat transfer during flow of permanent gas-liquid mixtures in tubes
11. Maximum heat transfer on surfaces immersed in fluidized beds
12. Heat transfer during boiling in tube bundles
13. Heat transfer during falling film evaporation.
14. Dryout during falling film evaporation.
15. Heat transfer during condensation in corrugated plate heat exchangers.
16. Heat transfer during gas-solid flow in pipes.
17. Heat transfer during condensation in coils.
18. Critical heat flux in coils.
19. Critical heat flux during saturated and subcooled flow across cylinders.
These predictive techniques have had extensive verification with world data and are considered to be the best or among the best available. These are included in most reference books and are widely used for the design and analysis of heat exchangers.
One of his major achievement was the use of Froude number to distiguish between the heat transfer between horizontal and vertical channels in his 1976 correlation. This method was adopted in all subsequent correlations developed by others.
Another important contribution has been the development of criteria for distinguishing between mini and macro channels. Using these criteria, he presented correlations for heat transfer during boiling and condensation in both mini and macro channels.
Evaporation from Water Pools
Using the analogy between heat and mass transfer, Dr. Shah developed formulas for evaporation from indoor and outdoor swimming pools which are also applicable to other types of pools such as those for storage of spent nuclear fuel. These formulas have been validated with all available test data. This is a very useful contribution as before it, empirical formulas based on forced convection were being used with unsatisfactory results. His publications on this subject have had more than 25,000 reads according to ResearchGate.
Miscellaneous Research
Following are some of Dr.Shah's other research works.
- Solar Power Plants: Designed and built a parabolic trough type solar collector to raise steam. Carried out theoretical analyses to evaluate the economic feasibility of such power plants.
- Binary Cycle for Power Plants: Carried out research to investigate the possibility of using a binary cycle with wet-dry cooling tower to increase output of power plants during winter. This could be very worthwile in cold climates.
- Pressure Transients in Buildings: Developed analytical formulas to calculate pressure transients in buildings. These are very useful for safety analyses for critical facilities such as nuclear power plants.
- Charge Air Cooling of Diesel Engines:Researched the potential of increasing engine output by cooling the charge air using a refrigeration compressor operated by a turbine driven by engine exhaust.
- Turbine Inlet Air Cooling: Investigated optimum alternatives for cooling of combustion air for combined cycle power plants with gas turbines. The alternatives considered included electrically driven chillers, steam driven chillers, absorptions chillers, with and without various types and sizes of thermal energy storage.
Development of Testing Facilities
- Designed and set up calorimetric test chamber for testing of window air conditioners at the Central Mechanical Engineering Research Institute (CMERI), Durgapur, India.It was designed to comply with Indian and ASHRAE standards.
- Designed and set up facilities for testing of refrigerators, water coolers, and compressors at CMERI. The facilities complied with Indian and ASHRAE standards.
Equipment Development
- Led the team that developed flake ice machines of 1, 3, 5, and 10 ton capacities. These have been manufactured and marketed by Kirloskar Pneumatic Company, Pune, India, since many years.
- Led the team that developed a 10 gallon per hour instantaneous water cooler for Century Refrigeration, Calcutta, India.