An instrument called a hotwire measures flow velocity by
determining the electrical power
required to keep a very small wire at a constant temperature in a
flow. The wire has a diameter D, and is
cooled by convection over the wire.
(a) For a fluid of arbitrary Prandtl number, develop an expression
for the fluid velocity in terms of the
difference between the wire temperature and the freestream
temperature.
(b) What is the velocity of air at 1 atm and 25°C, if a wire of 0.5
mm diameter is at 50°C while dissipating
35 W/m?
An instrument called a hotwire measures flow velocity by determining the electrical power required to keep...
Please show claer solve for ( a,c,d,e ) of this qustion. mm, electrical resistance per unit length An electrical transmission line (diameter: D=5 r=0.002 Ω/m) carries an electric current (1-100 A), dissipating an electrical power per unit length inr. On a windy day, the line is subjected to air flow (air temperature: T. -10C, air velocity V 50 km/hr) T, 10°C V 50 km/hr T, =? 1 -100 A air elec electrical line We would like to determine the surface...
Qi. A flat plate of width 1 m and length 0.2m is maintained at a temperature of 32°C. Ambient fluid at 22"C fBlows across the top of the plate in parallel flow. Determine the average heat transfer coefficient, the convection heat transfer rate from the top of the plate, and the drag force on the plate for the following: (a) The Buid is water flowing at a velocity of 0.5 m/s. o) Water is flowing at a velocity of 2.5...
just now i sent this questions. this is the answer given. however the answer i afraid that he used formula that is not for constant surface temperature and noncircular formula. this is the formula foe the noncircular tube. because the question ask about triangle. my problem is, i cannot answer question 1(b) that ask the heat transfer coefficient, h. please help me. thank you. this pic is a note on constant surface temperature. page 482 ref: HEAT AND MASS TRANSFER:...
summarizr the followung info and write them in your own words and break them into different key points. 6.5 Metering Chamber: 6.5.1 The minimum size of the metering box is governed by the metering area required to obtain a representative test area for the specimen (see 7.2) and for maintenance of reasonable test accuracy. For example, for specimens incorporating air spaces or stud spaces, the metering area shall span an integral number of spaces (see 5.5). The depth of...
summatize the following info and break them into differeng key points. write them in yojr own words apartus 6.1 Introduction—The design of a successful hot box appa- ratus is influenced by many factors. Before beginning the design of an apparatus meeting this standard, the designer shall review the discussion on the limitations and accuracy, Section 13, discussions of the energy flows in a hot box, Annex A2, the metering box wall loss flow, Annex A3, and flanking loss, Annex...