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.

Apiston-cylinder with a volume of 0.25 m3 holds 1 kg of air (r 0.287 k/kgk) at a temperature of 100 c. heat transfer to the cylinder causes an isothermal expansion of the piston until the volume triples. how much heat is added to the piston-cylinder?

Coiled springs ought to be very strong and stiff. si3n4 is a strong, stiff material. would you select this material for a spring? explain.

Afour cylinder four-stroke in-line engine has a stroke of 160mm, connecting rod length of 150mm, a reciprocating mass of 3kg and its firing order is 1-3-4-2. the spacing between cylinders is 100mm. i. show that the engine is in balance with regard to the primary inertia forces and primary 3. a and secondary inertia couples. li determine the out of balance secondary inertia force ii. propose ways of balancing this out of balance force and discuss the challenges that will arise