Question

2.19 The drag characteristics of a blimp traveling at 4 m/s are to be studied by experiments in a water tunnel. The prototype is 20 m in diameter and 110 m long. The model is one-twentieth scale. What velocity must the model have for dynamic similarity

Answer 1

`Vm=0.894m/s`

Step-by-step explanation:

From the question we are told that

Velocity if travel
`v=4m/s`

Diameter of prototype
`d_1=20m` and
`d_2=110m`

Scale ratio=
`(1)/(20)`

Generally Velocity of of the model using Froud's model is mathematically given as

`Fm=Fp`

`(Vm)/(√(Lmg)) =(Vp)/(√(Lpg))`

`Vm=Vp*(Vp)/(√(Lpg) )`

`Vm=4*(1)/(√(20))`

`Vm=0.894m/s`