Recent content by Ion Aguirre

No menace required. I daily work on fluid mechanics and I am not for teaching anybody. Please ban me at this forum Bye bye all

No doubts about your knowledge. But I think the asker is not at a fluid dynamics level but at a classic mechanics one. Im not writting to show how much I know, but for helping as much as I can.

Hi: From the data provided, there is no extrict solution for your question. Take into account, that, inside this context, Force is defined as the reason for bodies to change their motions. If there is no motion change, from the definition, Force cannot be computed. Solutions to this question...

Thats all a mater of MONEY. Relatively little tunnels, and models are a lot cheaper than the full scale option. As a teacher of mine said ... "Technical indecisivenes may exist, but economical one cannot".

Well, the problem with a Trebuchet, is that double pendulum. The dimensions and weight of both, the rigid arm(the lever) and the sling, are critical in order for the projectile to be shot at the required angle. It must be noted that, while at a simple catapult, the lever is stopped at a...

Hi The calculation of a trebuchet is not simple. Its composed by a double pendulum, working as a whip. The rigid arm is the only one which swinging angle is limited by design, while the sling angle isn't. Its not a hard device to be built, but its performance prediction calculation is not...

My apologizes

Adding speed or momentum does certainly increase energy. But how would that momentum be added ? In fact, there is a substraction, but not an addition. Rotational speed of the Earth and Earth-Moon system in slowering down, due to energy being continuosly "stolen" by the Tide effect from...

Most times, maths help for building what's named a "Model". A Model is a mathematical structure, founded on hypothesis and onservations, which predictions and results fit reality. Many times, we have no means to know how reality "really" is. Then, our Model becomes the only available working...

Lets check both figures and let's forget for a while the pipes at the bottom of the tanks: Neglecting everything about fluid dynamics, and centering only on basic physics ... The fluid inside the tank will flow down at a speed of: V= sqrt(dens g h). If the surface area of the free surface is...

Centrifugal force does not only affect the value of gravity on a planet, but the direction of its vector. If a weight is suspended by a rope, we all assume it points in a vertical line, but that's not right. Let's assume the planet as a sphere ... If the line drawn by the rope were extended...

Hi Houlahound We have no perfect propeller mathematical model by now. Anyway ...some notes ... Propeller thrust at working RPM: T= Kt dens N^2 D^4 Required torque at working RPM Q= Kq dens N^2 D^5 Kt and Kq are experimental coefficients dens --> fluid density N ------> Propeller rotation rate...

I can offer guidance. Hopefully no help needed.

Hi all: Im Ion, yes, like an unbalanced atom :-) Im from Spain, W Europe. Hope to be helpful Regards

Hi Holulahound: That's not a question of presure, but of density. Air is a compressible fluid, hence, density is not constant with pressure. Thrust and Torque of a propeller are directly related to density. Hence, when pressure changes, density changes as well and then, Thrust and Torque do the...