Where does the subcritical and supercritical flow occurs in hydraulic jump?

Where does the subcritical and supercritical flow occurs in hydraulic jump?

The depth upstream of a hydraulic jump is always supercritical, and the depth downstream of a hydraulic jump is always subcritical. It is important to note that the conjugate depth is different than the alternate depths for flow which are used in energy conservation calculations.

Can subcritical flow undergo a hydraulic jump?

A hydraulic jump is nonuniform flow. It occurs for supercritical flow on a subcritical channel slope.

What causes supercritical flow?

Critical flow is unstable and a small fluctuation in energy will shift the flow into supercritical or subcritical flow. Mild Slope is less than the critical slope and the normal depth is greater than critical depth (yn>yc). The flow is subcritical and controlled downstream.

What type of flow does a hydraulic jump belong to?

turbulent flow
The hydraulic jump is characterised by a highly turbulent flow. Macro-scale vortices develop in the jump roller and interact with the free surface leading to air bubble entrainment, splashes and droplets formation in the two-phase flow region.

How do you know if a flow is supercritical or subcritical?

If flow is subcritical waves will appear in front of the stick. If flow is at critical waves will have a 45 o angle. If flow is supercritical no upstream waves will appear and the wave angle will be less than 45 o. Note: Critical flow is unstable and often sets up standing waves between super and subcritical flow.

What is specific energy equation?

Specific Energy Equation Module 6. Energy at a particular point in the channel = Potential Energy + Kinetic Energy. where y is the depth of flow, v is the velocity, Q is the discharge, A is the cross- sectional flow area and E is the specific energy i.e energy w.r.t channel bottom.

Is supercritical flow bad?

Supercritical flow involves shallow water flowing in high velocity. Owing to swift flow of water in channels accommodating supercritical flow, there is considerable safety risk in the event of passengers falling into the channel and washed away to downstream.

What are the elements of hydraulic jump?

Hydraulic jump features The following features are associated with the transition from supercritical to subcritical flow:  Highly turbulent flow with significantly dynamic velocity and pressure components;  Pulsations of both pressure and velocity, and wave development downstream of the jump;  Two-phase flow due to …

When Froude number is between 1.7 and 2.5 the type of hydraulic jump is?

weak jump
Based on the Froude number hydraulic jump is classified as: If the Fr is in between 1.0 to 1.7, then it is known as undular jump. If the Fr is between 1.7 to 2.5, then it is known as a weak jump.

How do I find my Froude number?

It is generally expressed as Fr = v/(gd)1/2, in which d is depth of flow, g is the gravitational acceleration (equal to the specific weight of the water divided by its density, in fluid mechanics), v is the celerity of a small surface (or gravity) wave, and Fr is the Froude number.

What is the significance of Froude number?

The Froude number is used to compare the wave making resistance between bodies of various sizes and shapes. In free-surface flow, the nature of the flow (supercritical or subcritical) depends upon whether the Froude number is greater than or less than unity.

What is N in Manning’s equation?

The Manning’s n is a coefficient which represents the roughness or friction applied to the flow by the channel. Manning’s n-values are often selected from tables, but can be back calculated from field measurements.