Fundamentals of Heat and Mass Transfer
7th Edition
ISBN: 9780470501979
Author: Frank P. Incropera, David P. DeWitt, Theodore L. Bergman, Adrienne S. Lavine
Publisher: Wiley, John & Sons, Incorporated
expand_more
expand_more
format_list_bulleted
Videos
Question
Chapter 7, Problem 7.103P
(a)
To determine
The improvement in cooling rate.
(b)
To determine
Whether the heat rates for both arrangements change significantly if the air velocities were increased by a factor of 2.
(c)
To determine
The air mass rate requirement for the slotted nozzle arrangement.
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
Compute the Nu numbers for air at 40°C flowing with 4 m/s speed over the following:
1) A Copper sphere of 5 cm in diameter with 80°C isothermal surface temperature
2) A circular Aluminum pipe of 6 cm in diameter with 80°C isothermal surface temperature
3) A bank of 20x20 5-mm diameter tubes arranged in-line with center-to-center distance of
20 mm. Each tube is assumed to have isothermal temperature of 80°C.
Please show detailed calculations.
Experiments have been conducted on a metallic cylinder 12.7 mm in diameter and 94 mm
long. The cylinder is heated internally by an electrical heater and is subjected to a cross
flow of air in a low-speed wind tunnel. Under a specific set of operating conditions for
which the upstream air velocity and temperature were maintained at V = 10 m/s and
26.2°C, respectively, the heater power dissipation was measured to be P = 46 W, while the
average cylinder surface temperature was determined to be T, = 128.4°C. It is estimated
that 15% of the power dissipation is lost through the cumulative effect of surface radiation
and conduction through the endpieces.
Thermocouple for measuring
airstream temperature
Pitot tube for
determining velocity
Wind
tunnel
Power leads
to electrical heater
Heated
cylinder
Insulated
endpiece
Thermocouple
leads
1. Determine the convection heat transfer coefficient from the experimental observations.
2. Compare the experimental result with the convection coefficient…
Air at 2 atm. and 20oC is heated
as it passes through a tube of 25
mm ID with a velocity of 10m/s.
The temperature of the tube wall
is maintained at 100oC.
Calculate heat transfer per unit
length of the tube and the bulk
temperature change over a 3m
length of the tube
Chapter 7 Solutions
Fundamentals of Heat and Mass Transfer
Ch. 7 - Consider the following fluids at a film...Ch. 7 - Engine oil at 100C and a velocity of 0.1 m/s flows...Ch. 7 - Consider steady, parallel flow of atmospheric air...Ch. 7 - Consider a liquid metal (Pr1), with free stream...Ch. 7 - Consider the velocity boundary layer profile for...Ch. 7 - Consider a steady, turbulent boundary layer on and...Ch. 7 - Consider flow over a flat plate for which it is...Ch. 7 - A flat plate of width 1 m is maintained at a...Ch. 7 - An electric air heater consists of a horizontal...Ch. 7 - Consider atmospheric air at 25C and a velocity of...
Ch. 7 - Repeat Problem 7.11 for the case when the boundary...Ch. 7 - Consider water at 27°C in parallel flow over an...Ch. 7 - Explain under what conditions the total rate of...Ch. 7 - In fuel cell stacks, it is desirable to operate...Ch. 7 - The roof of a refrigerated truck compartment is of...Ch. 7 - The top surface of a heated compartment consists...Ch. 7 - Calculate the value of the average heat transfer...Ch. 7 - The proposed design for an anemometer to determine...Ch. 7 - Steel (AISI 1010) plates of thickness =6mm and...Ch. 7 - Consider a rectangular fin that is used to cool a...Ch. 7 - The Weather Channel reports that it is a hot,...Ch. 7 - In the production of sheet metals or plastics, it...Ch. 7 - An array of electronic chips is mounted within a...Ch. 7 - A steel strip emerges from the hot roll section of...Ch. 7 - In Problem 7.23. an anemometer design was...Ch. 7 - One hundred electrical components, each...Ch. 7 - The boundary layer associated with parallel flow...Ch. 7 - Forced air at 250C and 10 m/s is used to cool...Ch. 7 - Air at atmospheric pressure and a temperature of...Ch. 7 - Consider a thin, 50mm50mm fuel cell similar to...Ch. 7 - The cover plate of a flat-plate solar collector is...Ch. 7 - An array of 10 silicon chips, each of length...Ch. 7 - A square (10mm10mm) silicon chip is insulated on...Ch. 7 - A circular pipe of 25-mm outside diameter is...Ch. 7 - An L=1-m- long vertical copper tube of inner...Ch. 7 - A long, cylindrical, electrical heating element of...Ch. 7 - Consider the conditions of Problem 7.49, but now...Ch. 7 - Pin fins are to be specified for use in an...Ch. 7 - Prob. 7.52PCh. 7 - Prob. 7.53PCh. 7 - Hot water at 500C is routed from one building in...Ch. 7 - In a manufacturing process, long aluminum rods of...Ch. 7 - Prob. 7.58PCh. 7 - To determine air velocity changes, it is proposed...Ch. 7 - Determine the convection heat loss from both the...Ch. 7 - Prob. 7.63PCh. 7 - Prob. 7.64PCh. 7 - Prob. 7.67PCh. 7 - A thermocouple is inserted into a hot air duct to...Ch. 7 - Consider a sphere with a diameter of 20 mm and a...Ch. 7 - Prob. 7.76PCh. 7 - A spherical, underwater instrument pod used to...Ch. 7 - Worldwide. over a billion solder balls must be...Ch. 7 - Prob. 7.80PCh. 7 - Prob. 7.81PCh. 7 - Consider the plasma spray coating process of...Ch. 7 - Prob. 7.83PCh. 7 - Tissue engineering involves the development of...Ch. 7 - Consider temperature measurement in a gas stream...Ch. 7 - Prob. 7.89PCh. 7 - A preheater involves the use of condensing steam...Ch. 7 - Prob. 7.91PCh. 7 - A tube bank uses an aligned arrangement of...Ch. 7 - A tube bank uses an aligned arrangement of...Ch. 7 - Repeat Problem 7.94, but with NL=7,NT=10, and...Ch. 7 - Heating and cooling with miniature impinging jets...Ch. 7 - A circular transistor of 10-mm diameter is cooled...Ch. 7 - A long rectangular plate of AISI 304 stainless...Ch. 7 - A cryogenic probe is used to treat cancerous skin...Ch. 7 - Prob. 7.103PCh. 7 - Prob. 7.104PCh. 7 - Prob. 7.105PCh. 7 - Consider the packed bed of aluminum spheres...Ch. 7 - Prob. 7.108PCh. 7 - Prob. 7.109PCh. 7 - Prob. 7.111PCh. 7 - Packed beds of spherical panicles can be sintered...Ch. 7 - Prob. 7.114PCh. 7 - Prob. 7.116PCh. 7 - Prob. 7.117PCh. 7 - Prob. 7.118PCh. 7 - Prob. 7.119PCh. 7 - Prob. 7.120PCh. 7 - Dry air at 35°C and a velocity of 20 m/s flows...Ch. 7 - Prob. 7.123PCh. 7 - Benzene, a known carcinogen, has been spilled on...Ch. 7 - Prob. 7.125PCh. 7 - Prob. 7.126PCh. 7 - Condenser cooling water for a power plant is...Ch. 7 - Prob. 7.128PCh. 7 - In a paper-drying process, the paper moves on a...Ch. 7 - Prob. 7.131PCh. 7 - Prob. 7.132PCh. 7 - Prob. 7.133PCh. 7 - Prob. 7.134PCh. 7 - Prob. 7.136PCh. 7 - It has been suggested that heat transfer from a...Ch. 7 - Prob. 7.138PCh. 7 - Cylindrical dry-bulb and wet-bulb thermometers are...Ch. 7 - The thermal pollution problem is associated with...Ch. 7 - Cranberries are harvested by flooding the bogs in...Ch. 7 - A spherical drop of water, 0.5 mm in diameter, is...Ch. 7 - Prob. 7.143PCh. 7 - Prob. 7.144PCh. 7 - Prob. 7.145PCh. 7 - Prob. 7.146PCh. 7 - Prob. 7.147PCh. 7 - Consider an air-conditioning system composed of a...Ch. 7 - Prob. 7.149P
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, mechanical-engineering and related others by exploring similar questions and additional content below.Similar questions
- 7.43 Liquid sodium is to be heated from 500 K to 600 K by passing it at a flow rate of 5.0 kg/s through a 5-cmID tube whose surface is maintained at 620 K. What length of tube is required?arrow_forward5.7 The average Reynolds number for air passing in turbulent flow over a 2-m-long, flat plate is . Under these conditions, the average Nusselt number was found to be equal to 4150. Determine the average heat transfer coefficient for an oil having thermal properties similar to those in Appendix 2, Table 18, at at the same Reynolds number and flowing over the same plate.arrow_forwardLiquid ammonia is transported from a production plant to a processing center via a 0.6-m diameter pipeline at a mass flow rate of 0.15 kg/s. Surface temperature of the pipe is maintained 0°C by using a cooling jacket with ice-cold water. Ammonia enters the pipeline at -17°C and exits at -3°C. Assume the flow is both hydrodynamically and thermally fully developed in the pipe. What is the length of the pipe? 1857marrow_forward
- The pressure is 101.32 kPa and the air velocity at 316.5 k is 0.61m / s. The surface of the sphere is 277.76 k and its average diameter is 114 mm. Calculate the heat transfer coefficient for the air blown aroundarrow_forwardAir at atmospheric pressure and 25oC is heated in a tube with an ID of 25 mm. The tube wall is maintained at a temperature of 200oC. What length of tube is required to achieve an outlet air temperature of 120oC if the air flow is 10 Nm3/hr?arrow_forwardEngine oil flows through a 25-mm-diameter tube at a rate of 0.5 kg/s. The oil enters the tube at a temperature of 25°C, while the tube surface temperature is maintained at 100°C. (a) Determine the oil outlet temperature for a 5-m and for a 100-m long tube. For each case, compare the log mean temperature difference to the arithmetic mean temperature difference.arrow_forward
- Air that is fully-developed flows in a rectangular duct of inside dimensions 0.610 m x 0.305 m. The inlet air temperature is 21.1°C, and at outlet the air temperature is 26.7°C. If the mass flow of air is 2.72kg/h and the duct length is 2.44 m, calculate (a) the required heat in the form of a constant wall flux to heat the air and (b) the pressure drop due to friction. Also, solve for (c) h and (d) Ts,i.arrow_forwardIn the final stages of production, a pharmaceutical is sterilized by heating it from 25 to 75°C as it moves at 0.19 m/s through a straight thin-walled stainless steel tube of 12.7-mm diameter. A uniform heat flux is maintained by an electric resistance heater wrapped around the outer surface of the tube. If the tube is 10 m long, what is the required heat flux? If fluid enters the tube with a fully developed velocity profile and a uniform temperature profile, what is the surface temperature at the tube exit? Fluid properties may be approximated as p = 1000 kg/m³, cp = 4000 J/kg-K, μ = 2 × 10-³ kg/s-m, k = 0.8 W/m-K, and Pr = 10. Determine the required heat flux, W/m². q'" W/m² Determine the surface temperature at the tube exit, in °C. = i °C 8,0arrow_forwardIn the final stages of production, a pharmaceutical is sterilized by heating it from 25 to 75°C as it moves at 0.19 m/s through a straight thin-walled stainless steel tube of 12.7-mm diameter. A uniform heat flux is maintained by an electric resistance heater wrapped around the outer surface of the tube. If the tube is 10 m long, what is the required heat flux? If fluid enters the tube with a fully developed velocity profile and a uniform temperature profile, what is the surface temperature at the tube exit? Fluid properties may be approximated as p = 1000 kg/m³, c, = 4000 J/kg-K, µ = 2x 10-3 kg/s-m, k = 0.8 W/m-K, and Pr = 10. Determine the required heat flux, W/m². W/m2 Determine the surface temperature at the tube exit, in °C. T = °C i S,0 Physical Properties Mathematical Functionsarrow_forward
- In the final stages of production, a pharmaceutical is sterilized by heating it from 25 to 75°C as it moves at 0.21 m/s through a straight thin-walled stainless steel tube of 12.7-mm diameter. A uniform heat flux is maintained by an electric resistance heater wrapped around the outer surface of the tube. If the tube is 10 m long, what is the required heat flux? If fluid enters the tube with a fully developed velocity profile and a uniform temperature profile, what is the surface temperature at the tube exit? Fluid properties may be approximated as p = 1000 kg/m³, cp = 4000 J/kg-K, µ = 2x 10-3 kg/s-m, k = 0.8 W/m-K, and Pr = 10. Determine the required heat flux, W/m2?. q = i W/m? Determine the surface temperature at the tube exit, in °C. i °Carrow_forwardIn the final stages of production, a pharmaceutical is sterilized by heating it from 25 to 75°C as it moves at 0.21 m/s through a straight thin-walled stainless steel tube of 12.7-mm diameter. A uniform heat flux is maintained by an electric resistance heater wrapped around the outer surface of the tube. If the tube is 10 m long, what is the required heat flux? If fluid enters the tube with a fully developed velocity profile and a uniform temperature profile, what is the surface temperature at the tube exit? Fluid properties may be approximated as p = 1000 kg/m³, c, = 4000 J/kg-K, µ = 2x 103 kg/s-m, k = 0.8 W/m-K, and Pr = 10. Determine the required heat flux, W/m². q! = i W/m? Determine the surface temperature at the tube exit, in °C. i °C S,0arrow_forwardIn the final stages of production, a pharmaceutical is sterilized by heating it from 25 to 75°C as it moves at 0.22 m/s through a straight thin-walled stainless steel tube of 12.7-mm diameter. A uniform heat flux is maintained by an electric resistance heater wrapped around the outer surface of the tube. If the tube is 10 m long, what is the required heat flux? If fluid enters the tube with a fully developed velocity profile and a uniform temperature profile, what is the surface temperature at the tube exit? Fluid properties may be approximated as ρ=ρ= 1000 kg/m3, cp=cp= 4000 J/kg·K, μ=μ= 2 × 10-3 kg/s·m, k=k= 0.8 W/m·K, and Pr=Pr= 10.arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Principles of Heat Transfer (Activate Learning wi...Mechanical EngineeringISBN:9781305387102Author:Kreith, Frank; Manglik, Raj M.Publisher:Cengage Learning
Principles of Heat Transfer (Activate Learning wi...
Mechanical Engineering
ISBN:9781305387102
Author:Kreith, Frank; Manglik, Raj M.
Publisher:Cengage Learning
Heat Transfer – Conduction, Convection and Radiation; Author: NG Science;https://www.youtube.com/watch?v=Me60Ti0E_rY;License: Standard youtube license