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ECE5320 Mechatronics Assignment#01: Literature Survey on Sensors and Actuators Topic: Fluid Measurement Sensors. Prepared by: Daniel Plaizier Dept. of Electrical and Computer Engineering Utah State University E: ; T: ( 435)797-; F: (435)797-3054 (ECE Dept.)
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ECE5320 MechatronicsAssignment#01: Literature Survey on Sensors and Actuators Topic: Fluid Measurement Sensors Prepared by: Daniel Plaizier Dept. of Electrical and Computer Engineering Utah State University E: ; T: (435)797-; F: (435)797-3054 (ECE Dept.) W: http://mechatronics.ece.usu.edu 3/9/2007
Outline • Reference List • To Explore Further • Major Applications • Basic Working Principle • Typical Configuration • Major Specifications • Limitations • Purchasing Information ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Reference List • Beckwith, Thomas G; Marangoni, Roy D; Lienhard V, John H; “Mechanical Measurements”: Pearson Education, Inc., 5th, 1993 • www.efunda.com (March 07, 2007) • Bishop, Robert H.; “The Mechatronics Handbook”: Library of Congress Cataloging-in-Publication Data,2002; • http://www.engineeringtoolbox.com/flow-meters-d_493.html (March 07, 2007) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
To Explore Further • Those seeking more information concerning theory, analysis, and design of flow measurements should seek out Engineering databases and textbooks regarding fluid flow measurements and characteristic. (ie. www.ENGnetbas.com) • Those seeking more information on purchasing information and pricing should visit Engineering search engines, like www.globalspec.com, to find the appropriate fluid measurement appartatus. ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Major Applications • Aerospace • Medical • Public utilities • Environmental • Mining • Industrial • Research http://www.flexim.com/english/flow_applications.php http://www.tecplot.com/showcase/contours/issue_19/article01.htm http://en.wikipedia.org/wiki/Image:Gas_meter.JPG ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal • Types of flow meters (only principals concerning differential pressure flow meters will be addressed in this section) (Bishop Table 19.3) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal • To understand how many fluid flow meter, sensor, works an understanding of some fluid flow characteristics is necessary • Flow may be laminar, transitional, or turbulent • Flow may also be in a transient state or a steady-state for each of these flow types • Flow can be compressible or incompressible. (Only the incompressible flow will be addressed in these slides.) • Plus and understanding how the flow characteristics correspond with the Reynolds number and velocity profile for the fluid flow ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal • The Reynolds number is a dimensionless parameter used to determine whether or the flow is laminar or turbulent • Fluid properties: • ρ = density • V = velocity • D = characteristic length • μ = dynamic viscosity ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal • Relative magnitudes of the Reynolds number • Pipe: • Laminar – Re < 2300 • Turbulent – Re > 5x105 • Transitional state is between these values • Blood flow in the brain – Re = 100 • Person swimming – Re = 4x106 • Blue whale – Re = 3x108 • Typical pitch in Mayor League Baseball – Re = 2x105 * Reynolds number values where taken from the following website: http://en.wikipedia.org/wiki/Reynolds_number (March 07, 2007) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal • Velocity profile of fluid is a pipe • (a) laminar velocity profile ~ Re < 2300 • (b) turbulent velocity profile ~ Re > 5x105 • Notice that the turbulent velocity profile is closer to pipe wall. This is cause by the increased moment vector there. http://me.queensu.ca/people/sellens/teaching/fluids/power_law.php ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal • Velocity profile is also effected by the surrounding • Some attributes that contribute to changes in the velocity profile and the Reynolds number are the following: bend, weld, joint, valve, surface roughness (Bishop Figure 19.52) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal • Differential Pressure Flow meters utilize the Reynolds number and the velocity profile to determine whether or not this type of sensor is applicable for the given situation • Differential pressure flow meters are based off an energy equation that describes the fluid flow know as Bernoulli's Equation • Bernoulli’s Equation: ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Basic Working Principal • “The basic principle of nearly all differential pressure flow meters is that if a restriction is placed in a pipeline, then the pressure drop across this restriction is related to the volumetric flow rate of fluid flowing through the pipe.”* (Bernoulli’s Equation) • “The orifice plate is the simplest and cheapest type of differential pressure flow meter. It is simply a plate with a hole of specified size and position cut in it, which can then be clamped between flanges in a pipeline.”* *(Bishop Ch. 19 – pg. 64) (Bishop Figure 19.53) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
TypicalConfiguration • Venturi Tube: “A section of tube forms a relatively long passage with smooth entry and exit. A Venturi tube is connected to the existing pipe, first narrowing down in diameter then opening up back to the original pipe diameter. The changes in cross section area cause changes in velocity and pressure of the flow.” (www.efunda.com) www.efunda.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
TypicalConfiguration • Nozzle: “A nozzle with a smooth guided entry and a sharp exit is placed in the pipe to change the flow field and create a pressure drop that is used to calculate the flow velocity.” (www.efunda.com) www.efunda.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
TypicalConfiguration • Segmental Wedge: “A wedge-shaped segment is inserted perpendicularly into one side of the pipe while the other side remains unrestricted. The change in cross section area of the flow path creates pressure drops used to calculate flow velocities.” (www.efunda.com) www.efunda.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
TypicalConfiguration • V-Cone: “A cone shaped obstructing element that serves as the cross section modifier is placed at the center of the pipe for calculating flow velocities by measuring the pressure differential.” (www.efunda.com) www.efunda.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
TypicalConfiguration • Pitot Tube: “A probe with an open tip (Pitot tube) is inserted into the flow field. The tip is the stationary (zero velocity) point of the flow. Its pressure, compared to the static pressure, is used to calculate the flow velocity. Pitot tubes can measure flow velocity at the point of measurement.” (www.efunda.com) www.efunda.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
TypicalConfiguration • Averaging Pitot Tube: “Similar to Pitot tubes but with multiple openings, averaging Pitot tubes take the flow profile into consideration to provide better over all accuracy in pipe flows.” (www.efunda.com) www.efunda.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
TypicalConfiguration • Elbow: “When a liquid flows through an elbow, the centrifugal forces cause a pressure difference between the outer and inner sides of the elbow. This difference in pressure is used to calcuate the flow velocity. The pressure difference generated by an elbow flowmeter is smaller than that by other pressure differential flowmeters, but the upside is an elbow flowmeter has less obstruction to the flow.” (www.efunda.com) www.efunda.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
TypicalConfiguration • Dall Tube: “A combination of Venturi tube and orifice plate, it features the same tapering intake portion of a venturi tube but has a 'shoulder' similar to the orifice plate's exit part to create a sharp pressure drop. It is usually used in applications with larger flow rates.” (www.efunda.com) www.efunda.com ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
MajorSpecifications • Discharge coefficient • Flow coefficient • Turndown ratio • Line size • Accuracy • Flow rates • Operating temerature • Sensiticity • Resolution • Fluid type • Pressure range • Pipe connection type for in-line sensors • Response time ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Limitations • Pressure drop through flow meter/sensor cannot be recovered as illustrated in this chart ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
Limitations • No one flow meter can be used to measure most flow scenarios. It is vital that some knowledge be known about the flow type so an appropriate flow meter can be selected. • “In general the best flowmeter will be the one that can meet the performance specification at the lowest total cost (this is a combination of purchase price and cost of maintenance).” (Bishop Ch.19 – pg. 72) ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators
PurchasingInformation • Cost • $20 (http://www.hub4health.com/index.asp?PageAction=VIEWPROD&ProdID=85492) to • $2295 (http://www.omega.com/ppt/pptsc.asp?ref=FLR2000_FLV2000) • Where to buy: • www.omega.com • www.flowmeters.com • www.hedland.com/ • www.awcompany.com/ ECE5320 Mechatronics. Assignment#1 Survey on sensors and actuators