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What are the factors that affect the discharge coefficient value?

What are the factors that affect the discharge coefficient value?

In a single phase flow, the discharge coefficient depends mainly on the Reynolds number and the beta factor.

Why actual discharge is less than theoretical discharge?

The reason why Cd values are always less than 1 is because the actual discharge will always be less than the theoretical discharge idealized by Toricelli. This is so due to the effect of surface tension and friction from the external fluid.

Why do the discharge coefficients differ from unity?

The discharge coefficient differs from unity due to the nonuniformity of flow parameters (such as Mach number) at the nozzle exit and presence of boundary layer (viscous effect).

What is the significance of discharge coefficient?

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” …

Which of the following restrictor has the highest discharge coefficient?

Which of the following has highest coefficient of discharge ?

  • A. sharp edged orifice.
  • venturimeter.
  • Borda’s mouthpiece running full.
  • CipoUetti weir.

Why is the coefficient of discharge greater than 1?

In HEC-RAS the factor attached to the head loss through a culvert or bridge includes both the entrance and exit losses. In fact, the usual assumption is that the outlet loss is equal to the velocity head. This is why you get a factor greater than 1.

What does a high coefficient of discharge mean?

Coefficient of discharge is stated as the ratio between the actual flow discharge and theoretical flow discharge. In nozzle flow measurement, the efficiency of Cd is higher when compared to the flow measurement at the orifice. …

What is the range of coefficient of discharge?

The orifice discharge coefficients are in the range of 0.6-0.9 and are affected by the fluid viscosity and the size of the vena contracta in the orifice.

Is coefficient of discharge constant?

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.

What is the formula of coefficient of discharge?

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 Cd would always take that value.

How do you find the coefficient of discharge?

The discharge coefficient of an orifice or nozzle is defined as the ratio of the actual to theoretical flow rate:

  1. Cd=Measured Flow RateTheoretical Flow Rate (1)
  2. η=σΔp12ρ¯V2 (6)
  3. ξ=σΔp¯Δp (7)

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.

How do you calculate the coefficient of discharge for a nozzle?

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 …

Why is coefficient of discharge for Venturimeter greater than orifice meter?

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 …

Which is the cheapest device for measuring flow discharge rate?


Which flowmeter is most accurate?

Coriolis mass flow meters

How can we determine whether the flow is laminar or turbulent?

Explanation: Reynold’s number is used to determine whether the flow is laminar or turbulent. If Reynold’s number is less than 2000, it is a laminar flow. If Reynold’s number is greater than 2000, then it is a turbulent flow.

Which is the device for measuring flow velocity?


What is the use of flow velocity?

Flow velocity is the vector field that is used to describe fluid motion in a mathematical manner. The entire length of the flow velocity is referred to as the flow speed. Flow velocity in fluids is the vector field that provides the velocity of fluids at a certain time and position.

Which meter does not use an obstruction?

Magnetic flowmeters

What is normal water flow rate?

about 6 to 12 gallons per minute

How many GPM will a 3/4 pipe flow?

Assume Average Pressure. (20-100PSI) About 12f/s flow velocity
Sch 40 Pipe Size ID (range) GPM (with minimal pressure loss & noise)
1/2″ .50-.60″ 14 gpm
3/4″ .75-.85″ 23 gpm
1″ 1.00-1.03″ 37 gpm

What is normal flow rate?

Normal flow rate is 1 atmosphere (101.3 kPa) or 14.696 psia at 32 0F (0 0C). Actual flow rate is the actual volume of fluid that passes a given point based on given pressure and temperature of the process.

Is 2.5 gpm low flow?

Unfortunately, there is no firm definition of low-flow, but it’s generally accepted that anything using 1.5 gallons per minute (gpm) or less is considered “ultra low flow,” while anything using 2.5 gallons per minute to 1.5 gallons per minute is considered “low flow.” Nowadays, thanks to standards set by the government …

How many GPM can a 1 pipe flow?

Metric PVC Pipe

Assume Average Pressure. (20-100PSI) About 12f/s flow velocity
1/2″ .50-.60″ 14 gpm
3/4″ .75-.85″ 23 gpm
1″ 1.00-1.03″ 37 gpm
1.25″ 1.25-1.36″ 62 gpm

What is a good well flow rate?

5 gpm (two fixtures running simultaneously at 2.5 gpm) is a good estimate of peak demand, for the typical household. Water wells that reliably yield 5 gpm should be able to meet peak and daily needs for most residences. Wells yielding less than 5 gpm, however, are sometimes the only water source available.

Is 2 GPM good water pressure?

According to federal regulations, all kitchen and bathroom faucets should have a maximum flow rate of 2.2 gallons per minute (gpm) at 60 psi (pounds per square inch) of pressure; in California and Georgia, maximum flow rates are further restricted to 2.0 gpm (California will eventually be restricted to 1.8 gpm).