Radial vs Axial Turbine, diff in mechanical stress

[Chuck 65]

I am a hobbyist and I have designed a radial turbine device for use in a tidal stream. I have conducted a couple of experiments to demonstrate that there is less mechanical stress in the radial approach as compared to the axial approach but I would like to prove this concept mathematically (at a basic level). I have been able to find references to Eulers equation but (not being an engineer or physicist) am unable to figure out how to use the formula to show the difference. Can someone out there please explain the basic math principles that show why an axial turbine will have more mechanical stresses than a radial turbine?

W=(U2-U1) + (V2-V1) + (W2-W1) where U = Blade velocity, V = Absolute Velocity, W = Relative Velocity.

 

[LightHero]

In an axial turbine, U2-U1 is zero, while V2-V1 and W2-W1 are not, which results in more mechanical stress on the turbine. In a radial turbine, U2-U1 is not zero, while V2-V1 and W2-W1 are zero, resulting in less mechanical stress on the turbine.