The greater reduction (higher number, in this case 1.78:1) slows the propeller RPM and thus reduces the blade inflow speed. The lower inflow speed...
Hi aboatguy The strongest and most fatigue resistent alloy in salt water is Nickel Aluminum Bronze C95800. It is substantially better than...
Hi CET The flatbottom boat racing classes have dealt with the porpoising/blowover problem by perhaps the best design technology known, natural...
Hi dgruenwald I have some of the Navy data. Don Smith's Power-Vent is the best solution I have seen for the low speed to high speed...
The U.S. Navy developed some high speed surface propellers that were tested at low speeds in a cavitation tunnel. They achieved efficiencies of...
Hydrodrive Tunnel Hi Tom An inch of hard water over the top of the prop causes much less problem than an inch or two of mixed vapor and air...
Tunnel function Hi Tom There is a very important difference between a tunnel and using propeller height to transition to surface mode. The...
Tunnel Shape Hi Bob The tunnel length seems a bit short to me. If you make it a bit longer you can fill it in if needed. If it is too short it...
Tunnel Design Hi Clamsalot My work takes me under some of the best large motor yachts (www.softcav.com). I have seen good tunnels and very...
Hi Ted Operating 2-Inches submerged aft of the transom will most likely result in the propeller "sucking" air from the surface. This is called...
Hi Ted Your propeller will be operating as a surface propeller. Operation with as little as 30-Percent of the disk wet will give adequate...
