Hydro-Physics?

[johnsonm50]

It is good to see America's Einsteins are alive and well. Thanks for sharing knowledge that must have taken years to gather.

Ill be re-rereading for awhile & also say thanks.

[sws115]

after several days of re reading and meditation and clue from another site trend
i have found the problem i re ran all the numbers and it confirms a loss of down forse on the sponsons
thanks guys

[sam]

Lack of down force on the sponsons is usually called incorrect center of gravity ... I think someone suggested it to you earlier

[sws115]

Lack of down force on the sponsons is usually called incorrect center of gravity ... I think someone suggested it to you earlier

yes balance/downforse i even said it was out of balance and i didnt understand where the balance points should be , still dont quite know if its going to be perfic but its got to get better i would need for someone to say it should be here here and here
now if i may ask another ?
how do you calculate air pressure in the tunnel at differant speeds? and what effects that will have on the c o g or i it as simiple as once its balanced it will take all the power you can throw at it and stay on the water?
these engineering calculation,s are big learning curve

[sam]

You don't calculate "pressure in the tunnel" you calculate lift generated by angle of attack - average angle of attack as mentioned earlier in the thread. The faster you go the more lift will be generated, so truly, the boat can only be balanced for one speed.

The boat will be most stable when center of lift and center of weight are close together.

Jim Russell's book has all the formulas and calculations and explains the differences between true wings and "wings in ground effect", it is very thorough and detailed.

[sws115]

ok i follow that, but i just dont know how to get there
i have spoke with jim several times , wish he had a class i could attend
jim and i ran the numbers on the red boat and we got it running in the upper 80,s and he said it had 100 + in it and it is a tail dragger
i am not sure i could follow along without a tutor or i would already have jims pc program ,prop riding is way more complicated ,then tail dragging ,im a little frustrated with it right now ,so i need to clear the cob webs of confusion and mixed information between the two
and work threw it some how
thanks for listening
scott

[sws115]

i figured it out these extentions did the trick