Question

a=4 b=3(m/s) 06. The drag force. F.experienced by a submarine that moves at a great depth from the surface of the water is a function of the density . viscosity, speed and the transversal section of the submarine 1. An expert suggests that the nondimensional relationship that allows the calculation of Fis: AVEA (a) is the number of dimensionless parameters in the expression correct? Why? (b)Are the parameters correct? If not, correct them. (c) A geometrically similar model to that of the real submarine has been constructed, so that all the lengths of the model area of those corresponding to the submarine. The model is tested in a different liquid than water. The force of the real submarine when it moves at bm's is to be determined. At which speed should the model be tested? -10kg(ms),-1000 kg m-1.810kg(ms). P800 kg m)

Answer 1

(a) Yes the no. of dimensionless parameters in the expansion is 2 which is correct. There are 2 pi terms. According to buckingham pi theorem there must be (m-n) pi terms where "m" is the total no. of variables which is 5 and "n" is the no. of fundamental dimensions which is 3 (M,L,T). So there are 2 pi terms.

criven :- 2 f eura = f (eva д C leveon t ex evD Azad? M 4 1st a term and a term (6) The correct parametess are: CLO KF evd Por - © Lua loal 4 a 4 pa prototype model m> Vp z 3 ufs.

By Reynold's m modal law - (Re)m= (Rele पm 'P 18x3x 800x Vm x Lm 1.8x109 103 Vm= 2.7 m/s is the speed of the model