Engineering, 18.03.2021 01:20 jamarstand
Annealing is a process by which steel is reheated and then cooled to make it less brittle. Consider the reheat stage for a 100-mm-thick steel plate (r = 7830 kg/m3 , cp = 550 J/kg, k = 48 W/mK), which is initially at a uniform temperature of Ti = 200 C and is to be heated to a minimum temperature of 550 C. Heating is effected in a gas-fired furnace, where products of combustion at T[infinity] = 800 0C maintain a convection heat transfer coefficient of h = 250 W/m K on both surfaces of the plate.
A) Calculate the Biot number for this heat transfer process.
B) Can the lumped-capacitance approximation be used to analyze this transient heat transfer process?
C) Assuming that the lowest temperature in the plate is at its midplane, calculate the dimensionless temperature at the midplane of the plate when temperature is 550 oC
D) Using the one-term approximate solution for convective heat transfer into a semi-infinite medium, calculate the Fourier number required to achieve a temperature of 550 oC in the steel
E) Calculate the time required to achieve a temperature of 550 oC at the midplane of the plate.
Answers: 3
Engineering, 04.07.2019 18:10
Give heat transfer applications for the following, (i) gas turbines (propulsion) ) gas turbines (power generation). (iii) steam turbines. (iv) combined heat and power (chp). (v) automotive engines
Answers: 1
Engineering, 04.07.2019 18:10
At 12 noon, the count in a bacteria culture was 400; at 4: 00 pm the count was 1200 let p(t) denote the bacteria cou population growth law. find: (a) an expression for the bacteria count at any time t (b) the bacteria count at 10 am. (c) the time required for the bacteria count to reach 1800.
Answers: 1
Engineering, 04.07.2019 18:10
Condition monitoring is a major component of. (clo4) a)- predictive maintenance. b)-preventive maintenance c)-proactive maintenance d)-reactive maintenance.
Answers: 1
Engineering, 04.07.2019 18:10
What are the two (02) benefits, which may result from a successful implementation of preventive maintenance (pm) program in an organization? (clo3)a)- lean manufacturing b)-overlapping responsibilities c)-the planner is not qualified d)-accurate contractor information e)-reduction in equipment redundancies f)-accurate stores information
Answers: 3
Annealing is a process by which steel is reheated and then cooled to make it less brittle. Consider...
English, 10.05.2021 22:20
Mathematics, 10.05.2021 22:20
Biology, 10.05.2021 22:20
Mathematics, 10.05.2021 22:20
History, 10.05.2021 22:20
Mathematics, 10.05.2021 22:20
History, 10.05.2021 22:20
English, 10.05.2021 22:20
Computers and Technology, 10.05.2021 22:20