The discharge coefficient C depends on the beta ratio and Reynolds number .
How does the discharge coefficient vary with the flow rate?
Unlike the flow coefficient, discharge coefficient is dimensionless and almost constant value for any diameter of a single model. ... For the same high of fluid in the reservoir, higher is the discharge coefficient, higher is the flow rate, therefore the reservoir can be voided at shorter time.
How is coefficient of discharge calculated?
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.
How does Reynolds number affect discharge coefficient?
Also, in the equation for discharge coefficient, Reynolds number is in the denominator , which means if viscosity is higher, Reynolds number is lower, and the coefficient of discharge is also higher, which results in higher flowrate for the same pressure difference in front of and after the orifice.
What does the discharge coefficient depend on?
In a single phase flow, the discharge coefficient depends mainly on the Reynolds number and the beta factor . Dependence on Reynolds numbers is very weak (except low Reynolds numbers), so the performance of differential flow meters is rather insensitive to liquid viscosity.
What is the importance of coefficient of discharge?
An important element in this process is the discharge coefficient, which is defined as: “ In a nozzle or other constriction, the ratio of the mass flow rate at the discharge end of the nozzle to that of an ideal nozzle which expands an iden- tical working fluid from the same initial conditions to the same exit pressure ” ...
What is a typical coefficient of discharge?
A discharge coefficient c d = 0.60 may be taken as standard, but the value varies noticeably at low values of the Reynolds number. The pressure recovery is limited for an orifice plate and the permanent pressure loss depends primarily on the area ratio.
Does coefficient of discharge CE take effects on the flow rate?
It has no dimensions and depends directly on the rate of flow and velocity of working fluid. It is symbolized by C d and its value is different for each fluid depending on the kind of measurement of flow.
How do I know my actual discharge?
KV Actual discharge = Actual area at B × Actual velocity at B = Cc × Cu A 2gH ( ) we see that the relationship between the coefficients is Cd = Cc × Cu To determine the coefficient of discharge measure the actual discharged volume from the orifice in a given time and compare with the theoretical discharge.
Which is the cheapest device for measuring flow discharge rate?
Explanation: Orificemeter is the cheapest available device for measuring flow/discharge rate. 2. The principle of Orificemeter is same as that of Venturimeter.
Can coefficient of discharge 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.
What is coefficient of discharge in Venturimeter?
The discharge coefficient of a Venturi meter is typically 0.985 , but may be even higher if the convergent section is machined. Discharge coefficients for uncalibrated Venturi meters, together with corresponding uncertainties, are given in ISO 5167-1: 1991.
Which of the following restrictors has the highest discharge coefficient?
- A. sharp edged orifice.
- venturimeter.
- Borda’s mouthpiece running full.
- CipoUetti weir.
Why coefficient of discharge of an orifice meter is much smaller than Venturimeter?
In Venturi meter losses are less so coefficient of discharge is higher whereas in orifice meter due to no convergent and divergent cones there are more losses and hence its coefficient of discharge is less.In venturi meter losses are low due to steamline shape of the diffuser and the pressure gradient is not abrupt as ...
What is the discharge coefficient of an orifice?
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.
Is the coefficient of discharge a constant for all notches Why?
The coefficient of discharge for both notches is different due to the height of the depth water level . ... This is due to the space for the water to flow through the notch. For rectangular notch, the space of water it is constant for every depth.
