『Flow meter calculates flow rate』Related information(flow rotameter|digital flow meter|balo meter|hydraulic flow meter|volumetric meter|positive displacement meter|pitot tube flow meter|displacement meter|cfm meter|variable area flow meter|inline flow meter|differential pressure flow meter|calibrated flow meter|velocity meter|paddle wheel flow meter|oval gear flow meter|anemometer hvac|multiphase flow meter|doppler flow meter|thorpe tube flowmeter|heat flow meter)
1. Experimental principle and calculation formula of Venturi flowmeter
The experimental principle of Venturi flowmeter is based on the Venturi effect and Bernoullis law, and the calculation formula mainly involves the calculation of flow rate Q. Experimental principle: Venturi effect: When a fluid passes through a gradually contracting pipeline, the flow velocity will significantly increase. This is due to the decrease in cross-sectional area of the pipeline, which causes the fluid to accelerate in order to maintain continuity. Bernoullis law: In constant flow, an increase in velocity is accompanied by a decrease in pressure. The Venturi tube utilizes this principle to calculate flow rate by measuring the pressure difference between the Zen chain stop before and after the contraction section. Calculation formula: Basic flow formula: Without considering resistance, the flow rate Q can be calculated by the inner diameter d of the pipeline, the flow velocity difference, and the head difference Δ h. The formula is Q=d2/Δ h. However, please note that v1 and v2 refer to the flow velocity before and after the contraction segment, respectively, and this formula is a theoretical value. In practical applications, resistance needs to be considered. Actual flow formula: Due to the presence of resistance in the actual pipeline, the actual flow rate Q will be lower than the theoretical value. Therefore, it is necessary to introduce the flow coefficient μ for correction, with the formula Q=Q theory/μ. The value of μ is calculated by experimentally measuring the flow rate and head difference. When conducting experiments with a Venturi flowmeter, it is necessary to follow certain steps and pay attention to relevant matters to
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2. How is the flow rate displayed by the flowmeter calculated?
The calculation method of the flow rate displayed by the flowmeter depends on its type, and the core principle is to indirectly calculate the flow rate by measuring fluid parameters.
. 1. Differential pressure flowmeter calculates flow rate based on the pressure difference before and after the fluid flows through the throttling device. The formula is Q=C × ε× A × √ (2 Δ P/ρ), where C is the outflow coefficient, ε is the expandability coefficient, A is the orifice area, Δ P is the pressure difference, and ρ is the density of the source equilibrium fluid. 2. The electromagnetic flowmeter calculates the flow velocity by inducing the electromotive force of the conductive liquid. The relationship between the flow velocity interception v and the induced electromotive force E is E=B × D × v, and the formula for calculating the volumetric flow rate Q is Q=(π D ²/4) × v, where B is the magnetic induction intensity and D is the inner diameter of the pipeline3. The turbine flowmeter utilizes the proportional relationship between the turbine rotation frequency and the flow velocity. The formula is Q=f/K, where f is the turbine pulse frequency and K is the calibrated instrument coefficient. The flow rate is proportional to the frequency. Hail Sparrow 4. Vortex flowmeter calculates flow velocity based on vortex shedding frequency. Frequency f=St × v/d (St is the Strouhal number, d is the width of the vortex), flow rate Q=(π D ²/4) × v, where D is the inner diameter of the pipeline.
3. Principle and formula of orifice plate differential pressure flowmeter
Principle and formula of orifice
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