7.In the following, which one cannot enhance the convection heat transfer? ( )
Q: How important the forced and free convection know as a mechanical engineer?
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Q: Q) An apple has been put into a freezer at (-18°C) to be cooled. Initially, the apple is at a…
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Q: Q) An apple has been put into a freezer at (-23°C) to be cooled. Initially, the apple is at a…
A: Given:- Surrounding temperature, T∞=-23°C=250K Initial temperature of apple, Ti=15°C=288K…
Q: 12. The inner and outer glasses of a 2m x 2m double window are at 18 C and 6 C, respectively. If the…
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Q: A 3-m2 hot black surface at 80°C is losing heat to the surrounding air at 25°C by convection with a…
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Q: A coal with a higher heating value of 6,700 Kcal/kg is consumed at a rate of 600 kg/hr. in a water…
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Q: Consider a silicon wafer positioned in a furnace that is zone-heated on the top section and cooled…
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Q: A spherical pellet (ρ =1000 kg/m3 , c = 1000 J/(kg⋅K)) with a radius ro = 1 cm is cooled from an…
A: Given Data ρ =1000 kg/m3 , c = 1000 J/(kg⋅K) ro = 1 cm h = 100 W/(m2 K) Ans(a) k = 0.1 W/(m⋅K)…
Q: 7. An automobile engine consumes fuel at a rate of 22 L/h and delivers 55 kW of power to the wheels.…
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Q: 2. Losses by Natural Convection from diameter and 121.9 mm Cylinder. A vertical cylinder 76.2 mm in…
A: Given:
Q: • What is heat energy transfer to the body of kid crashed a peace of ice mass 0.025kg in his mouth…
A: Given Data: Mass of ice mice=0.025 kg Temperature T=36.5°C…
Q: A short brass cylinder (8530 kg/m3,Cp = 0.389 kJ/kg · °C, k =110 W/m · °C, and α= 3.39 x 10-5 m2/s)…
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Q: Q3) On a hot summer day, a student turns his fan on when he leaves his room at 9.00 am. When he…
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Q: The presence of thermal reservoir of a Geothermal Power Plant, supplements the generation of power…
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Q: Briefly discuss another ONE heat transfer mechanism between the human body and the environment in…
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Q: Which of the following simultaneous heat transfer mechanisms applicable to moving fluid; a. None of…
A: We have to find Which of the following simultaneous heat transfer mechanisms applicable to moving…
Q: Question 2: A circuit board houses on its surface 120 closely spaced logic chips, each dissipating…
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Q: Blowing your hands in winter to warm up is ...., rubbing your hands is ....., heat loss by Dewar's…
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Q: 19.12 A certoain double-pane window consists of two glass sheets, each 80 cm x 80 cm x 0.30 cm,…
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Q: tompelalure dimerence, d) conduction when the temperature at a point varies with time. d) A…
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Q: A 1-cm diameter, 1 % carbon steel sphere, initially at 200 ⁰C, is cooled by natural convection, with…
A: d=1cm
Q: A liquid flows inside a 3-cm diameter pipe, 5 meters long with an entering temperature of 350 °C.…
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Q: 7. A 3-m-internal-diameter spherical tank made of 1-cm thick stainless steel is used to store iced…
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Q: 2. (a) Consider a 25-cm-diameter spherical ball at 700 K suspended in air and assume the…
A: Note - As per our guidelines we are supposed to answeronly one question. Kindly repost other…
Q: 9) If the temperature of the sun were to suddenly double, by what multiplicative factor would the…
A: According to Stefan Boltzman law of radiation The thermal radiation rate is directly proportional to…
Q: 4. For a flat plate, the transition from the free convection boundary layer to the free convection…
A: Rayleigh number, Ra, is a dimensionless term utilized in the computation of normal convection. where…
Q: A device expends 152.03 kJ of energy while pressurizing 6.953 kg of water initially at 11.81°C. The…
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Q: To solve heat conduction equation, we have assumed O steady case O all of the above O constant…
A: The heat conduction equation is based on the Fourier law. It states that the heat transfer per unit…
Q: 1, Two parallel disks, 80 cm in diameter, are separated by a distance of 10 cm and completely…
A: Calculate the heat transfer between two Surfaces.
Q: Calculate the tons of refrigeration required to freeze in 4 hrs 3 mm of 10 deg C water on a skating…
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Q: Compute the heat to be removed from 110 kg of lean beef if it were to be cooled from 20°C to 4°C,…
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Q: öaslg äbäi With rise in temperature , the conductivity of the metals depending on temperature…
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Q: A circular plate of diameter (0.74 m) is placed some how 1.5 mețer above the room floor, if the…
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Q: prove that heat transfer is a path function?
A: Consider two processes 1-a-2-b-1 and 1-a-2-c-1 on a PV diagram. The expression for the energy…
Q: A 1600-W iron plate has a thickness of 5 mm, cross-sectional area of 300 cm^2. The room convection…
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Q: Name an example from daily life (different from the text) for each mechanism of heat transfer.
A: The three modes of heat transfer are conduction, convection, and radiation. 1)Conduction: It is a…
Q: Question 2:A circuit board houses on its surface120 closely spaced logic chips, each dissipating…
A: closely Logic chips = 120 Heat dissipation, Q = 0.12 W Heat transfer is negligible Area of the…
Q: Q4/The outside wall of a building 6 m high receives an average radiant heat flux from the sun of…
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Q: Q2/ A 4-m-internal-diameter spherical tank made of 1.75-cm-thick stainless steel (k 15 W/m °C) is…
A: Given: Internal radius r1=2mOuter radius r2=2+0.0175=2.0175mThermal conductivity (k)=15W/m°CInner…
Q: The air above the surface of a freshwater lake is at temperature TA while the water is at its…
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- In convection heat transfer, what mechanism heat transfer where the fluid moves due to the decrease in its density caused by increase in temperature? Select the correct response: O Natural convection Forced convection Density convection Radical convectionThe air at 1 ATM and 35⁰c flow through a cylinder 5 cm in diameter, at Velocity 50 cm/s. The surface temperature of the cylinder is guarded at 150⁰c. *)Count the heat Each cylinder length.Q1. Convection heat transfer coefficient does not depend on geometric parameters of the system (True/False) Q2. Forced convective heat transfer coefficient depends on type of flow (True/False) Q3. Increase in thermal conductivity increases the Nusselt Number (True/False) Q4. If the Nusselt number (Nu) is unity, the heat transfer is purely by convection (True/False) Q5. The thickness of the thermal boundary layer increases in the direction of flow (True/False) Q6. Increase in film thickness. convective heat transfer coefficient. Q7. The relative thickness of hydrodynamic and thermal boundary is better described dimensioniess number. Q8. In forced convection, the heat transfer coefficient strongly depends on. .dimensionless number. 09. Fin increase the heat transfer rates by increasing Q10. Thermal conductivity of the fin should be
- The correlation below is used to calculate the heat transfer coefficients for forced convection owing to laminar flow outside flat plates. k0.67 (vp)0.5 co.33 h = 0.644 D0.5µ0.17 Where h is in W/m²-K v is in m/s p is in kg/m³ Cp is in J/kg-K D is in m µ is in Pa-s What units must the constant 0.644 have? What should be the value of the constant when all units are converted to English units (masses in lbm, lengths in ft, temperatures in oR, times in h, energies in Btu)?If forced convection uses Reynolds number to account for fluid movement during forced convection, what dimensionless number is used for natural convection? A. Nusselt number B. Einstein number C. Grashof number D. Prandtl numberQ4/The outside wall of a building 6 m high receives an average radiant heat flux from the sun of 1100 W/m². Assuming that 95 W/m² is conducted through the wall, estimate the outside wall temperature. Assume the atmospheric air on the outside of the building is at 20°C. Ans. 170°C
- Table 3(a): Heater Power Q = 20 Watts Air Velocity (m/s) 0 1.0 2.0 3.0 Plate temperature, TH (°C) 36.9 53.8 54.6 54.5 Ambient Temperature, TA (°C) 23.3 23.3 23.3 23.3 Temperature Difference, h TH-TA (°C) (W/m²K) 13.6 30.5 31.3 31.2Q5B) A steel pipe of 170 mm inner diameter and 190 mm outer diameter with thermal conductivity 55 W/m. K is covered with two layers of insulation. The thickness of first layer is 25 mm (k = 0.1 W/m. K) and second layer thickness is 40 mm (k = 0. 18 W/m. K). The temperature of steam and inner surface of steam pipe is 320 °C and outer surface of insulation is 80 °C. Ambient air temperature is 25 °C. The surface coefficient for inside and outside surfaces are 230 W/m².K and 6 W/m².K respectively. Determine the heat loss per meter length of steam pipe and layer of contact temperatures and also calculate overall heat transfer coefficient.A 1600-W iron plate has a thickness of 5 mm, cross-sectional area of 300 cm^2. The room convection heat transfer coefficient is 25 W/(m^2K) with a temperature of 27 C. Determine the time required for the iron plate to drop from 1000 C to 50 C? Density, specific heat value and conductivity of the plate are 2650 kg/m^3, 900 J/(kgk) and 150 W/(mk), respectively. 15 minutes 45 minutes 25 minutes none 33 minutes
- A 1800-W iron plate has a thickness of 4 mm, cross-sectional area of 340 cm^2 . The room convection heat transfer coefficient is 20 W/(m^2K) with a temperature of 20 C. Determine the time required for the iron plate to drop from 850 C to 250 C? Density, specific heat value and conductivity of the plate are 2750 kg/m^3, 900 J/(kgK) and 180 W/(mK), respectively. a)500 seconds b)800 seconds c)450 seconds d)none e)635 secondsA 1800-W iron plate has a thickness of 4 mm, cross-sectional area of 340 cm^2. The room convection heat transfer coefficient is 20 W/(m^2K) with a temperature of 20 C. Determine the time required for the iron plate to drop from 850 C to 250 C? Density, specific heat value and conductivity of the plate are 2750 kg/m^3, 900 J/(kgK) and 180 W/(mK), respectively. 500 seconds 635 seconds O none 450 seconds 800 secondsA 1800-W iron plate has a thickness of 4 mm, cross-sectional area of 340 cm^2 . The room convection heat transfer coefficient is 20 W/(m^2K) with a temperature of 20 C. Determine the time required for the iron plate to drop from 850 C to 250 C? Density, specific heat value and conductivity of the plate are 2750 kg/m^3, 900 J/(kgK) and 180 W/(mK), respectively A) 500 seconds B) none C) 635 seconds D) 800 seconds 450 seconds