Fluid Mechanics - Engineering

Q1:

Location of vena-contracta in an orificemeter does not depend upon the

A type of orifice.

B density, viscosity & compressibility of the fluid.

C ratio of pipe diameter to orifice diameter.

D pipe roughness.

ANS:A - type of orifice.

The location of the vena contracta in an orifice meter does not depend upon the pipe roughness. Here’s an explanation of each option:

  • Type of Orifice: The type of orifice (e.g., sharp-edged, concentric, eccentric) does affect the characteristics of flow through the orifice and can influence the size and location of the vena contracta.
  • Density, Viscosity, and Compressibility of the Fluid: These properties affect the fluid flow characteristics, including the size and location of the vena contracta. However, the location of the vena contracta is primarily influenced by the flow conditions and the geometry of the orifice.
  • Ratio of Pipe Diameter to Orifice Diameter: This ratio affects the flow profile downstream of the orifice and can influence the size and location of the vena contracta.
  • Pipe Roughness: Pipe roughness does not significantly affect the location of the vena contracta. The vena contracta forms immediately downstream of the orifice where the jet of fluid reaches its minimum cross-sectional area.
Therefore, among the options provided, the location of the vena contracta in an orifice meter does not depend upon pipe roughness.