[ASME ASME 2018 Power Conference collocated with the ASME 2018 12th International Conference on Energy Sustainability and the ASME 2018 Nuclear Forum - Lake Buena Vista, Florida, USA (Sunday 24 June 2018)] Volume 2: Heat Exchanger Technologies; Plant Performance; Thermal Hydraulics and Computational Fluid Dynamics; Water Management for Power Systems; Student Competition - Experimental Investigation of Heat Transfer and Friction Factor Characteristics Using Helical Surface Ring Turbulators in an Annulli of Double Pipe Heat Exchanger