Methanol section: One question per day – knowledge on heat exchangers, etc. 2016.02.29
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Methanol section: One question per day – knowledge on heat exchangers, etc. 2016.02.29 1. The coolant in the automatic vaporization cooling method is ( ). (A) Water (B) Air (C) Ice (D) Frozen saline 2. For ordinary fluids, when Re〈( ), it is definitely laminar flow. (A) 2,000 (B) 4,000 (C) 6,000 (D) 10,000. 3. For turbulence, ( ). (A) Only axial velocity, with no radial velocity. (B) Turbulent viscosity does not change with the flow pattern or the distance from the pipe wall. (C) A very thin layer of laminar flow remains near the pipe wall. (D) Re must be greater than 4,000. 4. Regarding pipe flow, which factor has no influence on the change in the flow pattern of the liquid? ( ) (A) Geometric dimensions of the liquid (B) Average velocity of the liquid (C) Density and viscosity of the liquid (D) Surface tension of the liquid and Plan’s number Answer: B A C D
1. The coolant in the automatic vaporization cooling method is (B). (A) Water (B) Air (C) Ice (D) Frozen saline solution. 2. For ordinary fluids, when Re〈(A), flow is definitely laminar. (A) 2,000 (B) 4,000 (C) 6,000 (D) 10,000 3. For turbulence, (C). (A) Only axial velocity, with no radial velocity. (B) Turbulent viscosity does not change with the flow pattern or the distance from the pipe wall. (C) A very thin layer of laminar flow remains near the pipe wall. (D) Re must be greater than 4,000. 4. Regarding pipe flow, the factor that has no effect on the change in the flow pattern of the liquid is (D). (A) Geometric dimensions of the liquid (B) Average velocity of the liquid (C) Density and viscosity of the liquid (D) Surface tension of the liquid and Plan’s number
1. The coolant in the automatic vaporization cooling method is (B). (A) Water (B) Air (C) Ice (D) Frozen saline 2. For a general fluid, when Re〈(A), it is definitely laminar flow. (A) 2,000 (B) 4,000 (C) 6,000 (D) 10,000. 3. For turbulence, (C). (A) Only axial velocity, with no radial velocity. (B) Turbulent viscosity does not change with the flow pattern or distance from the pipe wall. (C) A very thin layer of laminar flow remains near the pipe wall. (D) Re must be greater than 4,000. 4. Regarding pipe flow, the factor that has no effect on the transition of the liquid’s flow pattern is (A). (A) Geometric dimensions of the liquid (B) Average velocity of the liquid (C) Density and viscosity of the liquid (D) Surface tension of the liquid and Plan’s number