A 25-mm-diameter hot surface at is cooled by an air jet exiting a 5-mm-diameter round nozzle with a velocity of 35 m/s and temperature of 25. The nozzle exit is 25 mm from the hot surface. Determine the percentage change in average heat transfer coefficient at the hot surface if the air is replaced with carbon dioxide or helium. Use material properties from reputable tables.
A 25-mm-diameter hot surface at is cooled by an air jet exiting a 5-mm-diameter round nozzle wi...
A 70-mm diameter hot solid rod is suspended in a room in which the air and walls are at 25°C., The surface temperature of the rod and its emissivity are 200°C and 0.8, respectively. The associated coefficient of convective heat transfer from the rod surface to the air is 15 W/m2.K. If the total heat loss from the surface area of the rod is estimated to be 947 W, what is the length of the rod? Area of both sides of the...
Problem 1 Consider a 15-mm by 15-mm chip that is cooled on its top surface by a 6 m/s flow of 25 °C air. Any heat transfer from its bottom surface to the circuit board is ignored. Because of the chip construction, the electrical power dissipated in the chip results in a uniform heat flux over the surface of the chip. If the maximum temperature that any part of the chip can experience is 80 "C, determine the maximum allowable...
In a collision of sufficient force, automobile air bags respond by electrically triggering the explosive decomposition of sodium azide (NaN3) to its elements. A 43.398 g sample of sodium azide was decomposed, and the nitrogen gas generated was collected over water at 22°C. The total pressure was 798.8 mmHg. How many liters of dry N2 were generated? An atmospheric chemist studying the pollutant SO2 places a mixture of SO2 and O2 in a1.14 L container at 825.7 K and 2.3...
Help? Q2) In a collision of sufficient force, automobile air bags respond by electrically triggering the explosive decomposition of sodium azide (NaN3) to its elements. A 43.398 g sample of sodium azide was decomposed, and the nitrogen gas generated was collected over water at 22°C. The total pressure was 798.8 mmHg. How many liters of dry N2 were generated? Q3) An atmospheric chemist studying the pollutant SO2 places a mixture of SO2 and O2 in a1.14 L container at 825.7...