What is the relationship between flow and velocity?

What is the relationship between flow and velocity?

Flow is a measure of air output in terms of volume per unit of time. The common units are litres per minute, cubic feet per minute (CFM), etc. Velocity refers to how fast the air is moving in distance per unit of time.

How the rotational speed can reflect the turbine efficiency?

It is observed that with the increase of isentropic velocity ratio, the turbine efficiency is increased. According to this figure, when the rotational speed is going to increase to a value higher than the design point, due to the increased isentropic velocity ratio, the turbine efficiency is increased.

Which is the Euler turbine equation?

The Euler turbine equation relates the power added to or removed from the flow, to characteristics of a rotating blade row. The equation is based on the concepts of conservation of angular momentum and conservation of energy. — the same sense as the angular velocity.

What causes the difference in flow velocity?

Changes of temperature and pressure may lead to changes of gas-liquid ratio and gas phase volume; thus, a change of flow velocity may be caused and vibration is induced.

What is relation between flow and pressure?

This relationship can be expressed by the equation F = Q/t. Fluid flow requires a pressure gradient (ΔP) between two points such that flow is directly proportional to the pressure differential. Higher pressure differences will drive greater flow rates. The pressure gradient establishes the direction of flow.

How do you calculate turbine speed?

To find tip speed, we need the rotor diameter and rotational rate. So assume a rotor diameter of 100m and a rotation rate (ω) of 15 revolutions/min, rpm. A Google search says to convert m/min to mph, multiply by 0.0372 [mph / m/min]. = 175 mph.

Which forces play a dominant role in increasing efficiency of a turbine?

1) Increase the turbine inlet temperature provided the turbine materials can stand the temperature or one has access to replacement parts that can withstand the temperatures. 2) Increase the pressure ratio. There is a limit to the efficiency increase depending upon the turbine inlet temperature.

How do you calculate turbine work?

The turbine work equals the enthalpy difference between the main steam and extraction point (1,474.1 – 1,299.7 Btu/lbm), plus the remaining steam (79.2 percent) that passes to the turbine exhaust (0.792*[1,299.7 – 871.0] Btu/lbm). In this case, the turbine work equates to 513.8 Btu/lbm.

Does flow rate increase with pressure?

Flow rate is the effect. Higher pressure causes increased flow rate. If the flow rate increases, it is caused by increased pressure.

How is work removed from the flow of a turbine?

If the tangential velocity decreases across a blade row (where positive tangential velocity is defined in the same direction as the rotor motion) then work is removed from the flow (this happens in a turbine). From the steady flow energy equation,

How are torque and angular velocity of opposite sign work?

If torque and angular velocity are of opposite sign work is being extracted from the fluid (a turbine). Here is another approach to the same idea:

Which is the correct equation for a turbine?

Equation ( 12.3) is called the Euler Turbine Equation. It relates the temperature ratio (and hence the pressure ratio) across a turbine or compressor to the rotational speed and the change in momentum per unit mass.

Which is the control volume for the Euler turbine equation?

Figure 12.2:Control volume for Euler Turbine Equation. Applying conservation of angular momentum, we note that the torque, , must be equal to the time rate of change of angular momentum in a streamtube that flows through the device