Session: 06-13 Innovations in Bottoming Cycles and Components

Paper Number: 152065

Numerical and Experimental Analysis of Optimized Bladeless Turbines 

The Tesla turbine, also known as a bladeless turbine, operates based on the principles of adhesion and viscosity. These turbines are a promising alternative to expansion valves in refrigeration cycle as they recover a part of expansion work and improve the COP of the cycle. This paper presents a comprehensive numerical analysis of a bladeless turbine prototype developed by Tree Associates, utilizing Computational Fluid Dynamics (CFD) to evaluate its performance under various conditions with air as the working fluid. An unstructured meshing approach with refined detailing around the nozzle region was employed to capture intricate flow characteristics and predict turbine performance accurately. Mesh sensitivity analysis was conducted to ensure grid independence and optimize computational efficiency. Velocity triangles were analyzed to understand flow behavior and energy transfer mechanisms. The study explores the impact of nozzle shape (flat to convergent-divergent), nozzle inclination(15 to 80 degrees), and the number of nozzles (2, 4, 6 & 8) on overall turbine performance. To validate the computational model and provide insights into real-world performance, an experimental counterpart was set up and tested. The results of the numerical simulations are compared with the experimental data. This analysis serves as a baseline for upcoming multiphase turbine simulations, guiding future optimization efforts.

Presenting Author: James Braun North Carolina State University

Presenting Author Biography: James Braun is an assistant professor in the school of Mechanical and Aerospace Engineering at North Carolina State University. He received his PhD from Purdue in 2019, performed a Research Master at the von Karman Institute for Fluid Dynamics in 2015 and has a Master’s degree from the KU Leuven in Belgium (2014). Prior to joining NC State, he was an assistant research professor at Purdue University. He did a postdoc at Purdue and was an ORISE fellow working with the National Energy Technology Laboratory (NETL).

Authors:

Sai Kiran Chikatimarla North Carolina State University
Bernard Killingbeck Tree Associates
Helber Antonio Esquivel Puentes Purdue University
Ramona Michelle Hilbert Purdue University
Eckhard A Groll Purdue University
James Braun North Carolina State University