# flow

 Whatisvolumetricflowrateandwhataresomeofthetypicalunitsofmeasure?  is the volume of fluid which passes through a given surface per unit time. The SI unit is m3 s-1 Metres per sec Whatismassflowrateandwhataresomeofthetypicalunitsofmeasure? Mass that passes through a point per time periodKg per min  The SI units are kg s-1  = mass flow rate,  How does mass flow rate differ from volumetric flow rate? Volume flow is used to speeds.  Mass flow ignores the concept of volume and deals with molecules flowing per unit time.  Whenwoulditbeimportanttoknowmassflowrateovervolumetricflowrate? As this is how you charge a customer Whatarethethreemajortypesoffluidthatweencounterinaprocess? GasesLiquidsLiquids with sediments What is velocity profile when related to flow in a pipe? Layers What is the Reynolds Number and who discovered it? Osborne ReynoldsThe number used to Define the type of flow in a process  WhatarethefactorsthataffecttheReynoldsNumber? Density and velocity 9. What is the unit of the Reynolds Number? Re What name is used to describe the flow with a Reynolds Number less than 2000 and what would its velocity profile look like? LaminarThat it is flowing in layers It looks like that pipe diagram that looks like a meddle podiumThe centre is ahead and each side steps down to the edge . What name is used to describe the flow with a Reynolds Number greater than 4000 and what would its velocity profile look like? Turbulant flowThe diagram that of the semi circle but at the top it is a tiny squiggly line What name is used to describe the flow with a Reynolds Number greater than 10000 and what would its velocity profile look like? ChaoticSome backwards some forwardsSort of swirling around .What name is used to describe the flow between 2000 and 4000 is said to be? Transitional 14. Why is it necessary to know the type of flow in relation to flow measurement? As this will deceide what type of flow measurement is used as there are many types for different applications  If a pump takes 2 hours to fill a 5000 litre tank. What is the flow rate in cubic meters per hour? What is the flow rate in litres per minute? 2 hours to fill a 5000 litre tank 5000^2=2500l/h 5000^120=2 hours to fill a 5000 litre tank 5000^2=2500l/h 5000^120=41l/min A 100 mm pipe has a flow rate of 150 litres per minute what is the velocity of the liquid? IftheSGoftheliquidis1.2,whatisthemassflowrate? 1. Draw diagram ALWAYS2. Convert all to metres100mm = 0.01m150L/min = .15m^/min3. Cross sectional areaPie x radius squared3.1416 x .005 = 0.015714. Volume = csa x lengthLength = volume / csa.15 / .01571 = 9.45 m/ min Mass = volume = csa x length.15m2 x .01m = .00015m3 = 1.5L =1.5L / min1.5 x1.2 = 1.8L/min with this material How long do you need to run the pump if you require 2500 litres of product and the pump flow rate is 20 litres per minute? 2500/20= 125minutes What effect do pipe elbows, valves and other disturbances have on the flow profil Of where the flow meter is located and installed   What is the general rule for locating flow meters next to pipe elbows and valves? 10 diameters before5 diameters after  20. Why do some flow meters need to have square root extraction? to make the reading linear 21. Describe how you would use a pressure transmitter to measure flow? A metre using  Bernoulli's principleAs the speed of a fluid increases the pressure within the fluid decreases  . What are different designs of orifice plate? What fluids are they used for? Concentric. Centre holeEccentric. BottomSegmental. Hole at topWether there are air bubbles, liquids with Bernoulli'ssolids, or just plain fluids Orifice plate like a multimeter It measures pressure on both ends of a resistor, simar to ohms law 23. What are the main disadvantages of orifice plates? wear and will drift over time.  How is a venturi tube used to measure flow and what type of sensor is used? forces the fluid into a small space like a plane wing  A DP transducer is used on both ends, S the speed of the fluid increases te pressure within the fluid decreases  25. What is a flow nozzle? flow nozzle is a compromise between the orifice plate and the venture tube.It's a half half mx between the 2 26. What is a pitot tube? A pitot tube is a pressure measurement instrument used to measure fluid flow velocity 27. Why is an annubar better than a pitot tube? The annubar takes multiple samples across a section of a pipe or duct 28. What type of flow does a rotating van and a nutating disc meter measure? Water . A turbine flow meter is not accurate when the flow is fully turbulent. What can be fitted to improve performance? Use flow conditioners 30. How does a Magflow meter work? A magnetic field is applied a the metering tube, which results in a potential difference proportional where producing electromagnetic induction.  31. Can you use a Magflow meter to measure the flow of distilled water? Yes Water is conductive 32. What are the precautions to be taken when installing a Magflow meter? Coriolis Flow Meter As an object moves from the centre to the circumference of a rotating disc it is subjected to an inertia that will tend to move it from its attempt to move in a straight direction. What type of flow meter uses this effect? Coriolis Flow Meter 34. Can the coriolis flow meter measure mass flow? uses bluff alternating vortices, like a flag pole. 35. What is the principle that a vortex meter uses? Definatly yes. Good for it 36. Can a vortex meter measure low flow rates? uses bluff alternating vortices, like a flag pole.  Describe how ultra sonic flow meters measure flow? An ultrasonic flow meter is a type of flow meter that measures the velocity of a liquid or gas (fluid) by using the principle of ultrasound. Using ultrasonic transducers, the flow meter can measure the average velocity along the path of an emitted beam of ultrasound, by averaging the difference in measured transit time between the pulses of ultrasound propagating into and against the direction of the flow. Ultrasonic flow meters are affected by the temperature, density and viscosity of the flowing medium. They are inexpensive to use and maintain because they do not use moving parts, unlike mechanical flow meters. 38. How does a flow meter that measures temperature work? The movement of a fluid passed an object can cause cooling. . Gases can be compressed. How does this affect its flow measurement? not sure 40. Describe several methods of measuring mass flow in gases? Boyles Law states that If the pressure of a gas increases and the temperature remains the same then the volume will decrease.Gay Lussac's Law States that if gas temperature increases and the pressure remains the same then the volume will increase. Authorgeorge123 ID164678 Card Setflow Descriptionflow Updated2012-08-01T11:27:01Z Show Answers