The famous Balje diagram (often referenced in Moustapha’s texts) plots efficiency against Specific Speed.
study focusing on deep learning for turbine blade optimization. from the 2003 book or a research paper that cites him? Axial and Radial Turbines - Amazon.com axial and radial turbines by hany moustaphapdf 2021
Note: This content is original educational material synthesized from public turbomachinery principles as taught by experts like Dr. Hany Moustapha. For the specific 2021 PDF, figures, or proprietary equations, please consult the original document directly. The famous Balje diagram (often referenced in Moustapha’s
The radial turbine (often called an inflow turbine) looks like a snail shell or a centrifugal pump. The fluid enters the stator nozzles, gains velocity, and slams into the rotating impeller blades. Axial and Radial Turbines - Amazon
This equation highlights a fundamental design difference: In axial turbines, $U$ is constant across the stage (ignoring radial variations), simplifying the energy transfer analysis. In radial turbines, the change in radius from inlet to outlet provides a significant contribution to the work output via the $U_1 C_\theta 1$ term, allowing for high pressure drops across a single stage.
Based on the 2021 perspective, Moustapha identifies several trajectories: