Q1: Choking in case of pipe flow means that a

ANS:A - specified mass flow rate can not be achieved.

Choking in the context of pipe flow refers to a restriction in the flow cross-sectional area, which limits the maximum mass flow rate that can pass through the pipe.

Explanation:

1. Choking Phenomenon:
   • Choking occurs when the flow velocity reaches the speed of sound (ccc) within the fluid. At this point, further reductions in pressure do not result in an increase in flow rate because the flow is already moving at the maximum speed possible for the prevailing conditions.
   • This condition is associated with a critical flow regime, particularly in compressible fluid dynamics, where changes in pressure no longer significantly influence the flow rate.
2. Characteristics:
   • Flow Limitation: Choking restricts the maximum mass flow rate that can pass through a given cross-sectional area of the pipe.
   • Pressure Drop: Increasing the pressure drop across the choked section of the pipe does not result in an increase in mass flow rate beyond a certain point.
   • Flow Velocity: Flow velocity at the choke point can approach the speed of sound, depending on the properties of the fluid and the conditions in the pipe.
3. Causes:
   • Choking can occur due to geometric constraints (e.g., sudden narrowing of the pipe), fluid properties (e.g., compressibility effects in gases), or operational conditions (e.g., high velocities).

Conclusion: