Numerical analysis of small scale axial and radial turbines for solar powered Brayton cycle application

In the current work two types of turbines, axial and radial turbine, with their three configurations, Single Stage Axial, Dual Stage Axial and Single Stage Radial turbines, for solar Brayton cycle applications have been parametrically investigated with the aim of figuring out their performance in terms of efficiency and power output. The mean line design for each turbine was effectively completed in order to figure out the initial guess for the dimensions, the power output and the efficiency. Consequently, the Computational Fluid Dimension CFD analysis was employed for the sake of visualising the 3-Dimentions behaviour of the fluid inside the turbine as well as determining the main output like the power output and the efficiency at different boundary conditions. These boundary conditions were selected to be compatible with a small scale solar powered Brayton cycle. An evaluation for some types of losses such as tip clearance and trailing edge losses as well as the total loss coefficient of the rotor of each configuration, in terms of pressure losses, has been established as well. The current paper deals with Small Scale Turbines SST ranged from 5 to 50 kW as a power output. The outcomes showed that the Dual stage axial turbine performances better at the off design conditions. By contrast, the single stage radial turbine achieved higher power output during the same operating conditions. The results of the CFD analysis have been successfully validated against the experimental work done by the researchers for small scale (axial) compressed air turbine in the lab

Experimental Study and 3D Optimization of Small-Scale Solar-Powered Radial Turbine Using 3D Printing Technology

Small-Scale Turbines (SSTs) are among the most important energy-extraction-enabling technologies in domestic power production systems. However, owing to centrifugal forces, the high rotating speed of SSTs causes excessive strains in the aerofoil portions of the turbine blades. In this paper, a structural performance analysis is provided by combining Finite Element Methods (FEM) with Computational Fluid Dynamics (CFD). The primary objective was to examine the mechanical stresses of a Small-Scale Radial Turbine (SSRT) constructed utilizing 3D printing technology and a novel plastic material, RGD 525, to construct a SSRT model experimentally. After introducing a suitable turbine aerodynamics model, the turbine assembly and related loads were translated to a structural model. Subsequently, a structural analysis was conducted under various loading situations to determine the influence of different rotational speed values and blade shapes on the stress distribution and displacement. Maximum von Mises and maximum main stresses are significantly affected by both the rotor rotational speed and the working fluid input temperature, according to the findings of this research. The maximum permitted deformation, on the other hand, was more influenced by rotational speed, while the maximum allowable fatigue life was more influenced by rotating speed and fluid intake temperature. Also, the region of the tip shroud in the rotor had greater deflection values of 21% of the blade tip width