Cho ống lồng ống làm bằng kim loại, ống trong có d1/d2 = 34/40, dài 2,5 m. Nhiệt độ dòng nóng 110oC, nhiệt độ trung bình dòng lạnh 80oC, mật độ dòng nhiệt qua tường là 14780 W/m.
a. Tính hệ số truyền nhiệt dài.
b. Tính tổng nhiệt lượng truyền qua trên tòan bộ ống.

Afull journal bearing has a journal diameter of 27 mm, with a unilateral tolerance of -0.028 mm. the bushing bore has a diameter of 27.028 mm and a unilateral tolerance of 0.04 mm. the l/d ratio is 0.5. the load is 1.3 kn and the journal runs at 1200 rev/min. if the average viscosity is 50 mpa-s, find the minimum film thickness, the power loss, and the side flow for the minimum clearance assembly.

Ahot wire operates at a temperature of 200°c while the air temperature is 20°c. the hot wire element is a tungsten wire of 5 um diameter and 2 mm in length. plot using excel current, heat transfer and heat generated by the wire for air velocity varying from 1-10 m/s in steps of lm/s? matlab the sensor voltage output, resistance, or assume nu 0.989 re033pr13 take air properties at tr (200°c20°c)/2 = 110°c properties of tungsten: c 0.13 kj/kg.k 3 p 19250 kg/m k (thermal conductivity) = 174 w/m.k

Derive the correction factor formula for conical nozzle i=-(1+ cosa) and calculate the nozzle angle correction factor for a nozzle whose divergence hal-fangle is 13 (hint: assume that all the mass flow originates at the apex of the cone.