【简答题】Compute the torsional shear stress and the angle of twist in degrees in an aluminum tube, 600mm long, having an inside diameter of 60 mm and an ouside diameter of 80 mm when subjected to a steady torq...
【单选题】For a double-pipe exchanger, the dimension of inner tube is Φ 19 × 2.5mm, and the dimension of outer tube is Φ 38 × 3mm, the equivalent diameter of the annular space d e is ( ).