21.When the fluid is moved over the heat transfer surface by an external force, such as that provided by a pump, which type of heat transfer is referred to? (A)Natural convection (B)Forced convection (C)Centrifugal heat transfer (D)Two-phase convection

21.When the fluid is moved over the heat transfer surface by an external force, such as that provided by a pump, which type of heat transfer is referred to?
(A)Natural convection
(B)Forced convection
(C)Centrifugal heat transfer
(D)Two-phase convection

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統計： A(41), B(162), C(65), D(34), E(0) #787846

詳解 (共 1 筆)

蔡捷仁

B1 · 2016/07/08

#1409692

當液體透過外力,如泵進行熱對流是屬於哪一種熱對流？

答：強制對流（forced convection)

9.Blowers are used with many diesel engines to supply the air necessary for combustion to the engine’s cylinders. When the pressure of this air is increased above atmospheric pressure, referred to as supercharging, the power output of engine is increased. In addition, in a two-stroke engine the air supplied by the blower helps to purge the engine’s cylinders of exhaust gas. This is referred to as scavenging. Based on these descriptions, please specify the correct statement. (A)The scavenging and supercharging processes share identical purpose of increasing the static pressure in the intake pipes. (B)The use of blow for scavenging and supercharging is due to its characteristics of high-pressure and low volumetric flow rate. (C)The blower for marine application is always the centrifugal type as it offers the high speed characteristic. (D)The scavenging in a two-stroke engine assists to purge the engine’s exhaust gas which has beneficial effect for combustion.

21.When the fluid is moved over the heat transfer surface by an external force, such as that provided by a pump, which type of heat transfer is referred to?
(A)Natural convection
(B)Forced convection
(C)Centrifugal heat transfer
(D)Two-phase convection

詳解 (共 1 筆)

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