Test: Dimensional & Model Analysis - 1 - Civil Engineering (CE) MCQ

Distorted - model can have vertical scale exaggeration or slope exaggeration. Therefore they are not geometrically similar. It may have either geometrical distortion, or material distortion or distortion of hydraulic quantities or a combination of these.

The Reynold’s model law shall be applied in the case of fully submerged objects,


The Reynold’s model law ensures dynamic; kinematic and geometric similarities.

If gravitational and inertial forces are the only important forces, then the Froude number must be the same in the model and prototype. Thus,

But g is same for both model and prototype

Now, Discharge = Area x Velocity
⇒ Q_r = A_r x V_r ⇒ Q_r = L_r² x (L_r)^1/2
⇒ Q_r = L_r^5/2

h₀ be the head of Orifice
h_p be the head of Pitot tube
Velocity of emergence of water from orifice can be given by  = 

Geometric similarity exists between the model and the prototype if the ratios of corresponding length dimensions in the model and the prototype are equal. Different model scales for horizontal and vertical dimension are used in a distorted model. Geometric similarity is achieved by using same model scale throughout.