The discharge coefficient
What is coefficient of contraction of Venturi meter?
The coefficient of contraction is defined as the ratio between the area of the jet at the vena contracta and the area of the orifice . The typical value may be taken as 0.611 for a sharp orifice (concentric with the flow channel). The smaller the value, the more effect the vena contracta has.
What is the use of coefficient of discharge?
In a nozzle or other constriction, the discharge coefficient (also known as coefficient of discharge or efflux coefficient) is the ratio of the actual discharge to the theoretical discharge, i.e., the ratio of the mass flow rate at the discharge end of the nozzle to that of an ideal nozzle which expands an identical ...
What is the equation of Venturi meter?
| Q = flow rate | A2 = Area 2 | P1 = Pressure 1 | P2 = Pressure 2 | rho = density |
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What is coefficient of discharge of orifice meter?
The discharge coefficient is a dimensionless number used to characterise the flow and pressure loss behaviour of nozzles and orifices in fluid systems. Orifices and nozzles are typically used to deliberately reduce pressure, restrict flow or to measure flow rate.
What is the purpose of Venturi meter?
A venturi meter is also called a venturi flowmeter. It is used to calculate the velocity of fluids in running through a pipeline . The fluid may be a liquid or a gas. The meter consists of a pipe with a narrowing throat that expands back to it’s original diameter on the other side of the choke point.
How do you calculate venturi flow rate?
- Preview: Venturi Flow Calculator.
- and.
- Therefore:
- and.
- Q mass = ρ · Q. Where: Q = volumetric flow rate (m 3 /s, in 3 /s) Q mass = Mass flowrate (kg/s, lbs/s) A 1 = area = Π · r 2 (mm 2 , in 2 ) A 2 = area = Π · r 2 (mm 2 , in 2 ) r 1 = radius inlet at A 1 (mm, in) r 2 = radius inlet at A 2 (mm, in)
What is the formula for discharge coefficient?
In Equation (14.18) the discharge coefficient C d = ( 2 / 3 ) ( 2 g / 3 ) = 1.705 in metric units and, in Equation (14.19), C ′ d = ( 2 / 3 ) 2 / 3 = 0.544 in non-dimensional units. If the flow passes through critical depth over a weir crest then it might appear that C d would always take that value.
Can a discharge coefficient be greater than 1?
In practice, the discharge coefficient cannot be greater than one . This is a fact. The error may be in compensating the values of the variables in the equation. Verifies units, values, and homogeneity of area values.
Why coefficient of discharge is calculated?
The discharge coefficient is the actual flow ratio with the theoretical flow and makes allowances for flow contractions and friction effects. The discharge coefficient is a function of the Reynolds number while the Reynolds number is a function of the flow rate calculated using the discharge coefficient value.
What are the main parts of a Venturi meter?
- Cylindrical Inlet Section.
- Conical convergent Section.
- Cylindrical throat and.
- Conical divergent outlet.
Does a venturi increase pressure?
The Venturi effect states that in a situation with constant mechanical energy, the velocity of a fluid passing through a constricted area will increase and its static pressure will decrease . ... The change in velocity also affects the pressure of the fluid.
Which is better Venturi or orifice?
The Venturi meter can handle large range of flow rates of fluid than the Orifice meter but once the Venturi meter is installed the range of flow rates it can handle becomes fixed. ... Thus, Orifice meters offer much more flexibility of operation.
How is orifice coefficient calculated?
It is defined as the ratio of the actual discharge from an orifice to the theoretical discharge from the orifice . It is denoted by. If Q is actual discharge and is the theoretical discharge then mathematically is given as = The value of varies from (0.61) to( 0.65).
How do I calculate flow rate?
Q=Vt Q = V t , where V is the volume and t is the elapsed time. The SI unit for flow rate is m 3 /s, but a number of other units for Q are in common use. For example, the heart of a resting adult pumps blood at a rate of 5.00 liters per minute (L/min).
Which is the cheapest device for measuring flow rate?
Explanation: Orificemeter is the cheapest available device for measuring flow/discharge rate. 2. The principle of Orificemeter is same as that of Venturimeter.
