Maximum Velocity in Circular Channel Section

The maximum velocity in a circular channel section occurs when the flow is at the critical depth, which is defined as the depth of flow at which the specific energy is minimum. The specific energy is defined as the energy per unit weight of the fluid in a channel section.

Ratio of Depth of Flow to Diameter

The ratio of the depth of flow to the diameter of the circular channel section is a critical parameter that determines the maximum velocity of flow in the channel. This ratio is denoted by the symbol y/D, where y is the depth of flow and D is the diameter of the channel.

For maximum velocity in a circular channel section, the ratio of the depth of flow to the diameter of the channel is given by the following expression:

y/D = 0.81

This means that the depth of flow should be 0.81 times the diameter of the channel to achieve maximum velocity in the channel.

Explanation of Option A

Option A states that the ratio of the depth of flow to the diameter of the channel is 0.81, which is the correct answer.

Option B states that the ratio is 0.5, which is too small to achieve maximum velocity in the channel.

Option C states that the ratio is 0.85, which is close to the correct answer but still not accurate enough.

Option D states that the ratio is 1.0, which implies that the depth of flow is equal to the diameter of the channel, which is not correct for achieving maximum velocity in the channel.

Conclusion

In conclusion, the ratio of the depth of flow to the diameter of the circular channel section is a critical parameter that determines the maximum velocity of flow in the channel. For maximum velocity in a circular channel section, the ratio of the depth of flow to the diameter of the channel should be 0.81.