Holooly Plus Logo
Holooly Plus Logo

Question 6.60: A 1:30 scale model study of a submarine is proposed in an at...

A 1:30 scale model study of a submarine is proposed in an attempt to study the influence of a suggested shape modification. The prototype is 2 m in diameter, and it is designed to travel at 15 m/s. The model is towed in a water tank at 2 m/s, and a drag force of 2.15 N is measured. Does similitude exist for this test? If so, predict the power needed for the prototype.

The "Step-by-Step Explanation" refers to a detailed and sequential breakdown of the solution or reasoning behind the answer. This comprehensive explanation walks through each step of the answer, offering you clarity and understanding.
Our explanations are based on the best information we have, but they may not always be right or fit every situation.
The Blue Check Mark means that this solution has been answered and checked by an expert. This guarantees that the final answer is accurate.
Learn more on how we answer questions.

This Question has been Answered.

Subscribe

Already have an account?

Login

Related Answered Questions

Nondimensionalize the energy equation using a characteristic velocity U, length l, and temperature T0. Express the dimensionless parameter that results in terms of the Prandtl number

Verified Answer:
u^* =\frac{u}{U}, v^* =\frac{v}{U } , T^*=...

A fluid flows in a horizontal pipe of diameter d (Fig. P6.74). The flow is suddenly increased to an average velocity V. Show that the appropriate Navier–Stokes equation, using the coordinates shown, simplifies to

Verified Answer:
The only velocity component is u. Continuity then ...

A golf ball has dimples to increase its flight distance. Select the best reason that accounts for the longer flight distance of a dimpled ball compared to that of a smooth ball (A) The shearing stress is smaller on the dimpled ball (B) The dimpled ball has an effective smaller diameter

Verified Answer:
(C)

Normalize Euler’s equation using a characteristic velocity U, length l, pressure ρU^2, and time l/U. Determine any dimensionless parameters introduced in the normalized equation.

Verified Answer:
V^* =\frac{V}{U}, t^* =\frac{tU}{\ell } , \...

Normalize the continuity equation using a characteristic velocity V, length l, density ρ0, and time f^{-1}, where f is the frequency. What dimensionless parameter is introduced?

Verified Answer:
\rho ^* =\frac{\rho }{\rho _0}, t^* =tf , ...

An underwater study of a porpoise is to be performed by using a 1:10 scale model. A porpoise swimming at 10 m/s and making one swimming motion each second is to be simulated. What speed could be used in the water channel, and for that speed, how many swimming motions per second should be used?

Verified Answer:
Re_m=Re_p . ∴ \frac{V_m\ell _m}{\nu _m} =\...

A 1:10 scale model of a propeller on a ship is to be tested in a water channel. What should be the rotational speed of the model if the rotational speed of the propeller is 2000 rpm and: (a) The Froude number governs the study? (b) The Reynolds number governs the study?

Verified Answer:
a) Fr_m=Fr_p .         \frac{V_m^2}{\ell _...

A 1:20 scale model of an aircraft is tested in a 23°C wind tunnel. A speed of 200 m/s is used in the model study. A drag force of 10 N is measured. What prototype speed and drag force does this simulate if the elevation is:

Verified Answer:
Mach No. is the significant parameter: M_m...

A model study of a dirigible (a large balloon that travels through the air) is to be performed. The 10-m-diameter dirigible is to travel at 20 m/s. If a 40-cm-diameter model is proposed for use in a wind tunnel, or a 10-cm-diameter model for use in a 20°C water channel, which should be selected?

Verified Answer:
Re_p =\frac{20\times 10}{1.5\times 10^{-5}}...

The propeller of a ship is to be studied with a 1:10 scale model. (a) Assuming that the propeller operates close to the surface, select the propeller speed of the model if the prototype speed is 600 rpm. (b) What torque would be expected if 1.2 N•m is measured on the model?

Verified Answer:
Neglect viscous effects, and account for wave (gra...