Multi-parameter experimental study of a tesla turbine applied to an organic Rankine cycle system for low-grade heat utilisation

In response to the increasing demand for energy efficiency enhancement, the exploitation of low-grade thermal energy through Organic Rankine Cycle (ORC) systems has emerged as a crucial strategy for sustainable energy recovery. However, conventional expanders face limitations in terms of cost-effectiveness and efficiency optimization. This study presents a comprehensive experimental investigation into the performance characteristics of a Tesla turbine, an innovative bladeless expander, integrated within an ORC system operating under low-grade thermal conditions (90–130 °C). A prototype miniature ORC system incorporating a Tesla turbine-generator assembly was developed to systematically evaluate the turbine’s isentropic efficiency , its dynamic interactions with system parameters, and associated mechanical losses . Through a series of controlled experiments, key operational parameters including heat source temperature, pump speed (750–1170 RPM), and load current (0.4–1.9 A) were systematically varied to analyze the isentropic efficiency, power output , and pressure ratio relationships. The experimental results demonstrate that the Tesla turbine achieves a remarkable peak isentropic efficiency of 62.28 % and generates a maximum output power of 31.76 W under the tested conditions, with comprehensive analysis of the system’s heat absorption characteristics. This research represents the first multi-parameter experimental validation of a Tesla turbine in an ORC system, establishing its viability for low-grade heat recovery applications. The findings provide valuable insights for the development of scalable solutions in distributed energy systems and industrial waste heat recovery implementations.