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
Textbook Question
Chapter 7, Problem 7.99P
Heating and cooling with miniature impinging jets has been proposed for numerous applications. For a single round jet, determine the minimum jet diameter for which Equation 7.71 may be applied for air at atmospheric pressure (a) at
Expert Solution & Answer
Want to see the full answer?
Check out a sample textbook solution
Students have asked these similar questions
A plane-inclined pad thrust bearing is 160mm wide and 40mm long in the direction of sliding. The sliding velocity is 6 m/s and the bearing is supported so that the inlet film thickness is always three times the outlet film thickness. A load 18 kN is carried by the bearing and Tellus 37 oil is supplied at an inlet temperature of 40̊ C. Assuming that 80% of the heat generated in the bearing is carried away by the oil, describe the operating characteristics of the bearing (Pm, Q, F, tm,). Density is 875 kg/m3 and specific heat is Cp=1.880 J/g-K.
10A.5. Free convection velocity.
(a) Verify the expression for the average velocity in the upward-moving stream in Eq. 10.9-16.
(b) Evaluate 3 for the conditions given below.
(c) What is the average velocity in the upward-moving stream in the system described in Fig.
10.9-1 for air flowing under these conditions?
Pressure
Temperature of the heated wall
Temperature of the cooled wall
Spacing between the walls
Answer: 2.3 cm/s
T3=0°F.
Wall
1 atm
100°C
20°C
0.6 cm
-T₂ = 61°F
Surface temperatures
-T₁ = 69°F of plastic panel
Plastic panel has
thermal conductivity
k = 0.075
Btu/hr. ft. °F
(average value between
T₁ and T₂)
-0.502"
Fig. 10A.6. Determination of the thermal resistance of
a wall.
Problems 321
11B.6. Transpiration cooling in a planar system. Two large flat porous horizontal plates are sepa-
rated by a relatively small distance L. The upper plate at y = L is at temperature T₁, and the
lower one at y = 0 is to be maintained at a lower temperature To. To reduce the amount of
heat that must be removed from the lower plate, an ideal gas at To is blown upward through
both plates at a steady rate. Develop an expression for the temperature distribution and the
amount of heat qo that must be removed from the cold plate per unit area as a function of the
fluid properties and gas flow rate. Use the abbreviation = pCpv,L/k.
Answer:
edy/Let
1-e
k(T₁ - To) Φ
L
T-TL
To - TL
Problems 365
; 9⁰ =
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
Additional Engineering Textbook Solutions
Find more solutions based on key concepts
What parts are included in the vehicle chassis?
Automotive Technology: Principles, Diagnosis, And Service (6th Edition) (halderman Automotive Series)
9.14
(a) Given
and
calculate
(b) Given
and
, calculate L.
(c) Given
and
, calculate
.
Applied Statics and Strength of Materials (6th Edition)
1.1 What is the difference between an atom and a molecule? A molecule and a crystal?
Manufacturing Engineering & Technology
ICA 8-36
A 10-liter [L] flask contains 1.3 moles [mol] of an ideal gas at a temperature of 20 degrees Celsius [...
Thinking Like an Engineer: An Active Learning Approach (3rd Edition)
Assume that the air in Problem 3-22 is supplied to the space at 53 F (12 C). Compute the volume flow rate of th...
Heating Ventilating and Air Conditioning: Analysis and Design
Air flowing isentropically through a converging nozzle discharges to the atmosphere. At the section where the a...
Fox and McDonald's Introduction to Fluid Mechanics
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
- A long, cylindrical, electrical heating element of diameter D = 14 mm, thermal conductivity k = 251 W/m ⋅ K, density ρ = 2,805 kg/m3, and specific heat cp = 903 J/kg ⋅ K is installed in a duct for which air moves in cross-flow over the heater at a temperature and velocity of 30°C and 9 m/s, respectively. (a) Neglecting radiation, estimate the steady‐state surface temperature when, per unit length of the heater, electrical energy is being dissipated at a rate of 1,033 W/m.arrow_forwardHand Sanitizer (70% propanol gel) needs to be transported on a floor in a hospital from a central location per floor. The room farthest from the source is 17.5-m away. The hand sanitizer enters the tubing at 20°C and 275 kPa absolute and exits the tubing at atmospheric conditions. The tubing can Flowrate/velocity Calculation. Hand sanitizer be considered smooth; however, there are two (2) 90° curved elbows and four (4) Tee Run throughs, and one (1) foot value (Refer to the Loss for Fittings table in Canvas). The density of the hand sanitizer is 955 kg/m3 and the viscosity is 4.5 cP. What is the flow rate that can be obtained if the tubing diameter is 4.5-mm?arrow_forwardA heat treat steel plate measures 3 m *1 m and is initially at 30 degree Celsius. It is cooled by blowing air parallel to 1 m edge at 9 km/hr. If the air is at 10 degree Celsius. Estimate the convective heat transfer from both sides of the plate.arrow_forward
- Show all working explaining detailly each step. Answer Qb(i), (ii) & (iii)arrow_forwardA long, cylindrical, electrical heating element of diameter D = 12 mm, thermal conductivity k = 240 W/m ⋅ K, density ρ = 2,856 kg/m3, and specific heat cp = 908 J/kg ⋅ K is installed in a duct for which air moves in cross flow over the heater at a temperature and velocity of 30°C and 10 m/s, respectively. (a) Neglecting radiation, estimate the steady‐state surface temperature when, per unit length of the heater, electrical energy is being dissipated at a rate of 1,238 W/m.arrow_forwardShow your complete solution.arrow_forward
- 6.64 Consider application of the naphthalene sublimation technique (Problem 6.63) to a gas turbine blade that is coated with naphthalene and has a surface area of A, = 0.05 m². Airflow V,T_ - Turbine blade with naphthalene coating A., T., P. (T₂) To determine the average convection heat transfer coef- ficient for a representative operating condition, an experiment is performed in which the coated blade is exposed for 30 min to atmospheric air at the desired velocity and a temperature of T = 27°C. During the experiment the surface temperature is T. = 27°C, and at its conclusion the mass of the blade is reduced by Am = 8 g. What is the average convection heat transfer coefficient associated with the operating condition?arrow_forwardSolve it correctly please. I will rate accordingly with 3votes.arrow_forwardO. Air with free stream temperature of 10 C is flowing over a flat plate (1.5m long and Im wide). The air is flowing along 1.5m side of the plate. The plate is maintained at 90'C. Find the velocity of air required to have a rate of heat dissipation as 3.75 kW. Use the correlations: Nu =0.664Reos Pro33 for laminar flow Nu, = (0.037RE-871)Pr3 for turbulent flow Take the properties p = 1.0877 kg/m u=2.029×10 m/s, k=0.028 W/mK, C,-1.007KJ/kg.K and Pr-0.703arrow_forward
- Consider two cases involving parallel flow of dry air at V = 4.5 m/s, T, = 45°C, and atmospheric pressure over an isothermal plate at T = 20°C. In the first case, Re= 5x 105, while in the second case the flow is tripped to a turbulent state atx = 0 m. At whatx -location, in m, are the thermal boundary layer thicknesses of the two cases equal? What are the local heat fluxes, in W/m?, at this location for the two cases? x = i m Jam i W/m? i W/m? I turbarrow_forwardYou are designing a pin-style heatsink for forced cooling of an IC. A small fan blows RT air into the heatsink at about 2.3 ? ? . The aluminum pins are 2mm in diameter and have a constant surface temperature of 120°?. The heatsink is 100mm x 100mm and the pins have an inline arrangement with a transverse pitch of 4mm and a longitudinal pitch of 6mm. What is the total heat dissipation of this heatsink? The pins are 30mm high. Note RT=25 celsiusarrow_forwardAir at 22˚C and at atmospheric pressure flows over a flat plate at a velocity of 1.65 m/s. If the length of the plate is 2.179 m and its temperature is 98 ˚C, Calculate Heat rate by using exact and approximate methods both. What is the %age difference of the heat transfer rate values by these methods? Take width of the plate as unity. Properties given at 60˚C are as follows: Density: 1.058 kg/m3 , cp = 1.005 kJ/kg˚C, k= 0.02897 w/m˚C, Kinematic viscosity is 18.97 × 10-6 m2 /sarrow_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