Q: One end of a 0.3-m-long steel
One end of a 0.3-m-long steel rod is connected to a wall at 204oC. The other end is connected to a wall that is maintained at 93oC. Air is blown across the rod so that a heat transfer coefficient of 1...
See AnswerQ: Both ends of a 0.6-cm copper U-
Both ends of a 0.6-cm copper U-shaped rod are rigidly affixed to a vertical wall as shown in the accompanying sketch. The temperature of the wall is maintained at 93oC. The developed length of the rod...
See AnswerQ: A circumferential fin of rectangular cross section, 3.7-
A circumferential fin of rectangular cross section, 3.7-cm OD and 0.3 cm thick, surrounds a 2.5-cm- diameter tube as shown below. The fin is constructed of mild steel. Air blowing over the fin produce...
See AnswerQ: A wall with a thickness L is made of a material with
A wall with a thickness L is made of a material with a thermal conductivity that varies with its thickness x according to the equation, k=(ax +b) W/mK, where a and b are constants. If the heat flux ap...
See AnswerQ: A turbine blade 6.3 cm long, with cross-
A turbine blade 6.3 cm long, with cross-sectional area A = 4.6 3 10-4 m2 and perimeter P = 0.12 m, is made of stainless steel (k = 18 W/m K) . The temperature of the root, Ts, is 482oC. The blade is e...
See AnswerQ: To determine the thermal conductivity of a long, solid 2.
To determine the thermal conductivity of a long, solid 2.5-cm-diameter rod, one half of the rod was inserted into a furnace while the other half was projecting into air at 27oC. After steady state had...
See AnswerQ: Heat is transferred from water to air through a brass wall (
Heat is transferred from water to air through a brass wall (k = 54 W/m K) . The addition of rectangular brass fins, 0.08 cm thick and 2.5 cm long, spaced 1.25 cm apart, is contemplated. Assuming a wat...
See AnswerQ: The wall of a liquid-to-gas heat exchanger has
The wall of a liquid-to-gas heat exchanger has a sur- face area on the liquid side of 1.8 m2 (0.6 m * 3.0 m)with a heat transfer coefficient of 255 W/m2 K. On the other side of the heat exchanger wall...
See AnswerQ: The top of a 30-cm I-beam is maintained
The top of a 30-cm I-beam is maintained at a temperature of 260oC, while the bottom is at 93oC. The thick- ness of the web is 1.25 cm. Air at 260oC is blowing along the side of the beam so that / The...
See AnswerQ: The handle of a ladle used for pouring molten lead is 30
The handle of a ladle used for pouring molten lead is 30 cm long. Originally the handle was made of 1.9 cm * 1.25 cm mild steel bar stock. To reduce the grip temperature, it is proposed to form the ha...
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