Quick Answer: What Is Critical Depth Meter?

What is alternate depth?

Alternate depths are defined as the depths of flow in open channels for which the specific energy is the same.

The derived equation would be helpful in practical studies dealing with the open-channel flows, especially in the cases of transitions in width and bottom elevation of the channel..

What is it called when the hydraulic jump is in a moving form?

Explanation: When the hydraulic jump is dynamic or in a moving form it is called as positive surge.

What is normal depth of flow?

Normal depth is the depth of flow in a channel or culvert when the slope of the water surface and channel bottom is the same and the water depth remains constant. Normal depth occurs when gravitational force of the water is equal to the friction drag along the culvert and there is no acceleration of flow.

What does happen when the gate opening is more than the critical depth?

If the gate opening is equal or greater than the critical water depth, no hydraulic jump would occur, and the gate will not able to regulate the flow in that case (Yen et al.

Why do hydraulic jumps occur?

A hydraulic jump occurs when the upstream flow is supercritical (F>1). To have a jump, there must be a flow impediment downstream. The downstream impediment could be a weir, a bridge abutment, a dam, or simply channel friction. Water depth increases during a hydraulic jump and energy is dissipated as turbulence.

How do you calculate hydraulic jump?

Equations for Hydraulic Jump Calculations y2/y1 = (1/2)[-1 + (1 + 8Fr12)1/2] ; V1 = Q/(by1) ; and Fr1 = V1/(y1g)1/2. The upstream velocity, V1 and upstream Froude number, Fr1, need to be calculated first, using the last two equations, then the downstream depth of flow, y2 can be calculated using the first equation.

What is bed slope?

The depth–slope product is used to calculate the shear stress at the bed of an open channel containing fluid that is undergoing steady, uniform flow. … It is the product of the water depth and the mean bed slope, along with the acceleration due to gravity and density of the fluid.

What is the critical depth?

Critical depth is defined as the depth of flow where energy is at a minimum for a particular discharge.

How do you calculate critical depth?

The critical depth for a rectangular channel can be calculated from the fact that the Froude number is equal to one at critical flow conditions. For a rectangular channel , this fact leads to the equation: Vc/(gyc)1/2 = 1, where the subscript c is used to indicate critical flow conditions for the velocity and depth.

What is Hydraulic depth?

For use in Froude number and energy relationships in open channel flow hydraulics, mean depth, hm, is defined as the depth which, when multiplied by the top water surface width, T, is equal to the irregular section area, A, shown on figures 2-4a and 2-4b, of the flow section and is commonly used for critical flow …

What does Froude number tell you?

The Froude Number is a dimensionless parameter measuring the ratio of “the inertia force on a element of fluid to the weight of the fluid element” – the inertial force divided by gravitational force. … A Froude number of 1 defines critical mean depth vs. critical velocity.

What is critical depth oceanography?

In biological oceanography, ‘Critical Depth’ is defined as a hypothesized surface mixing depth at which phytoplankton growth is precisely matched by losses of phytoplankton biomass within this depth interval. … This concept is useful for understanding the initiation of phytoplankton blooms.

How is alternate depth calculated?

The depths of flow can be either PR = y1 or PR` = y`1. These two possible depths having the same specific energy are known as alternate depths. In Fig. (5.1), a line (OS) drawn such that E = y (i.e. at 450 to the abscissa) is the asymptote of the upper limb of the specific energy curve.

Why is critical depth important?

Critical depth is a quantity of fundamental importance to understanding the flow characteristics. If the actual depth is greater than critical depth, then the flow is considered “subcritical”. Subcritical flow is “slow flow” and is impacted by downstream conditions.

How do you calculate critical flow rate?

Then it continues downstream and the pressure bounces back (or recovers). The coefficient for this recovery is the Critical Flow Factor. It is discovered by dividing the downstream pressure after vena contracta by the downstream pressure at vena contracta, then calculating the square root of that number.

How is the critical depth affected by Q?

How critical depth is affected by the Q? As shown in the results, when the flow rate (Q) is lower, the critical depth is shallower. When the flow rate (Q) is higher, the critical depth is deeper.

What is hydraulic jump in fluid mechanics?

A hydraulic jump is a fluid shockwave created at the transition between laminar and turbulent flow. … Friction against the sink surface slows the flow until an abrupt change occurs. At this point, the depth increases as water piles up in the transition region and flow becomes turbulent [1].