A thermocouple is inserted into a hot air duct to measure the air temperature. -me thermocouple
Consider conditions for which the air velocity in the duct is
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Fundamentals of Heat and Mass Transfer
- A thermocouple junction is in the form of 8 mm diameter sphere. Properties of materialare: Cp = 420 J/kg-K; ρ = 8000 kg/m3 ; k = 40 W/m-K; h = 40 W/m2 -K. This junction isinitially at 40 oC and inserted in a stream of hot air at 300 oC. Find the following:a. Time constant of the thermocouple.b. The thermocouple is taken out from the hot air after 10 seconds and kept in still airat 30 oC. Assuming the heat transfer coefficient in air is 10 W/m2-oC, find thetemperature attained by the junction 20 seconds after removal from hot air.arrow_forwardFROM BOOK: ENGINEERING THERMOFLUIDS, M. MASSOUDarrow_forwardFast plz hand written.... I'll upvote if hand written plz asaparrow_forward
- Write legibly, provide manual step by step solution, and diagram for below given problem. Saturated steam at 500oK flows in a 0.20 m inside diameter, 0.21 m outside diameter pipe. The pipe is covered with 0.08 m of insulation with a thermal conductivity of 0.10 W/m-K. The pipe’s conductivity is 52 W/m-K. The ambient temperature is 300oK. The unit convective coefficients are h1 = 18,000 W/m2-K and ho = 12 W/m2-K. Determine the heat loss from 4 m of pipe. a. 778.21 watts b. 825.80 watts c. 830. 80 watts d. 835.80 wattsarrow_forwardCalculate the critical and actual heat flux for pool boiling of water at 2.1 bar from a surface at 130 °C. Take: Saturation temperature =123 °C PL= 941.6 kg/m', pv=1.18 Ca= 4.25 KJ/kg.°C K=687*10 W/m°C HL=230*10“ Ns/m2 2=2198 KJ/Kg 0=55*10 N/m Pw at 125°C = 2.5*10$ N/m² P,=2.25*10 N/m²arrow_forwardQ. IsTeam at 605 K Flow in Alpipe with thermal conductivity K=188 W/m.c whose in and out diamter D₁ = 2 inche and D₂= 58 mm respectively. The pipe is covered with Turo insulation material First was glass wool K=0,06 and second cyas insulation K=0,01 w/m.c. Firs.T 33mm and second 13 mm, Heat is Lost to the surrounding al Too Too2 = 288K by natural convection and radiation, with combined. heat Transfer coefficent of he-22,8 W/m²c. Taking heat Transfer coefficent inside pipe To be hi-48.9 W/m² c. Find Heat loss poo length and Temp. dropp. ?? *arrow_forward
- Conduction 1. A thermodynamic analysis of a proposed Brayton cycle gas turbine yields P= 5 MW of net power production. The compressor, at an average temperature of T. = 400°C, is driven by the turbine at an average temperature of T₁ = 1000°C by way of an L = 1m-long, d= 70mm - diameter shaft of thermal conductivity k = 40 W/m K. Compressor min T Combustion chamber Shaft L Turbine Th out (a) Compare the steady-state conduction rate through the shaft connecting the hot turbine to the warm compressor to the net power predicted by the thermodynamics- based analysis. (b) A research team proposes to scale down the gas turbine of part (a), keeping all dimensions in the same proportions. The team assumes that the same hot and cold temperatures exist as in part (a) and that the net power output of the gas turbine is proportional to the overall volume of the device. Plot the ratio of the conduction through the shaft to the net power output of the turbine over the range 0.005 m s Ls 1 m. Is a…arrow_forwardIf hand written i'll upvote otherwise downvote?...arrow_forwardThe steel pipe has an internal radius of 50 mm., a thickness of 5 mm. and a length of 5 m. Inside the pipe, hot fluid with temperature 80 C flows inside the pipe and cold fluid with temperature 20 C flowing outside the pipe. Let k=285 W/mC and hi= 25 W/mC, ho= 10 W/mC. Find 4.1) Heat Transfer Rate (Q) 4.2) Temperature on both inner and outer tube surfaces...arrow_forward
- For Heat transfer through cylinder tube wall, the temperature is to be a linear function of r (radius) of the tube. Select one: O True O False The conductivity of H20 in solid form (ice) is higher than that of H20 in liquid form (water). Select one: O True O False F, (Correction factor for temperature in some heat exchangers) should be 1.0 or greater than 1.0 in some cases. Select one: O True Falsearrow_forward1. Saturated steam at 500 K flows in a 0.20 m inside diameter, 0.21 m outside diameter pipe. The pipe is covered with 0.08 m of insulation with a thermal conductivity of 0.10 W/m-K. The pipe's conductivity is 52 W/m-K. The ambient temperature is 300 K. The unit convective coefficients are h; = 18,000 W/m²-K and ho = 12 W/m²-K. Determine the heat loss (kJ/min) from 4 m of pipe. • show conversions, units, and box in your final answersarrow_forwardThe condenser of a steam power plant consists of AISI 302 Stainless steel tubes, each with outer and inner diameters of 35 mm and 30 mm, respectively. Saturated steam at 0.135 bar condenses on the outer surface of the tube, while water at a mean temperature of 295 K is in fully developed flow through the tube (you can assume that 295 K is the mean temperature in the axial direction of the tube (e.g. along its length) or you may assume that the inlet water temperature is 295 K). For a water mass flow rate of 0.22 kg/s, what is the outer surface temperature of the tube and the rates of heat transfer and steam condensation per unit tube length? As an approximation you may evaluate the properties of the liquid film at the saturation temperature.arrow_forward
- Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning