In the boiler of a power plant are tubes through which water flows as it is brought from 0.8 mpa, 150°c to 240°c at essentially constant pressure. the total mass flow rate of the water is 100 kg/s. combustion gases passing over the tubes cool from 1067 to 77 °c at essentially constant pressure. the combustion gases can be modeled as air as an ideal gas. there is no significant heat transfer from the boiler to its surroundings. assuming steady state and neglecting kinetic and potential energy effects, determine (a) the mass flow rate of the combustion gases, in kg/s (b) the rate of exergy destruction, in kj/s. (c) the exergetic efficiency given by. let t0 = 25°c, p0 = 1 atm. round your answers to 3 significant digits.

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.

10 kg of co2 is initially contained at 400 kpa and 300 k. the gas constant for carbon dioxide is 189 j/lkg k) and has a specific heat ratio, k, of 1.289. isentropic expansion then occurs until the pressure is 200 kpa. a) determine the initial volume of co2 in m. b) determine the final temperature in k. c) determine the work done by the system during the expansion kl.

Tom is having a problem with his washing machine. he notices that the machine vibrates violently at a frequency of 1500 rpm due to an unknown rotating unbalance. the machine is mounted on 4 springs each having a stiffness of 10 kn/m. tom wishes to add an undamped vibration absorber attached by a spring under the machine the machine working frequency ranges between 800 rpm to 2000 rpm and its total mass while loaded is assumed to be 80 kg a) what should be the mass of the absorber added to the machine so that the natural frequency falls outside the working range? b) after a first trial of an absorber using a mass of 35 kg, the amplitude of the oscillation was found to be 10 cm. what is the value of the rotating unbalance? c) using me-3.5 kg. m, find the optimal absorber (by minimizing its mass). what would be the amplitude of the oscillation of the absorber?