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Mechanical Engineering
Explain the fundamental characteristics of a boundary layer, including laminar, transitional, and turbulent regimes.
Mechanical Engineering
Calculate Reynolds number, if a fluid having viscosity of 0.4 Ns/m2 and relative density of 900 kg/m3 through a pipe of 20mm with a velocity of 2.5 m.
Mechanical Engineering
A bushed-pin type flexible coupling is used to connect two shafts and transmit 5 kW power at 720 r.p.m. Shafts, keys and pins are made of commercial steel (S= Se = 240 N/mm) and the factor of safety is 3. The flanges are made of cast iron FG 200 (S= 200 N/mm) and the factor of safety is 6. Assume, Say = 0.5 S and S 0.5 S There are 4 pins. The pitch circle diameter of the pins is four times of shaft diameter. The permissible shear stress for pins is 35 N/mm. The permissible bearing pressure for rubber bushes is 1 N/mm. The keys have square cross-section. su Calculate: (i) diameter of the shafts; (ii) dimensions of the key; (iii) diameter of the pins; (iv) outer diameter and effective length of the bushes.
Mechanical Engineering
In automobile,Which device evens out the engine's output for a nice smooth ride?
Mechanical Engineering
15 mm dia SS (Young’s modulus = 200 Gpa) rod is coated with HA (Young’s modulus = 300 Gpa).
A) What should be the coating thickness so that the Young’s modulus of the composite is 210 Gpa (use mixture rule)?
B) If the densities are 7.9 and 4.0 gm/cc, what is the average density?
A) What should be the coating thickness so that the Young’s modulus of the composite is 210 Gpa (use mixture rule)?
B) If the densities are 7.9 and 4.0 gm/cc, what is the average density?
Mechanical Engineering
Two guitar strings of the same known length L, and same known linear mass density mu vibrate at their common fundamental frequency of f1 Hz. you would like to know the frequency, f1, of the note you hear, but you don't have perfect pitch. Undeterred, you decide to use physics to find it. Both strings originally have some unknown T. You can increase the tension of one of the strings such that you known its tension is exactly 10% greater than that for the other one. Use your knowledge of interference and beats to find the orignally frequency, f1, in terms of the number of beats per second that you hear, n
Mechanical Engineering
I’m stuck with this example question. Some explanation and work through would be appreciated
An ideal gas enters a horizontal heating pipe at a temperature of 200oC, and with a specific enthalpy of 400 "kJ/ kg" .
As it travels along the pipe heat is added at constant pressure, and the air leaves the heater at a temperature of 300℃.
No work is done on the gas during the heating process.
The gas velocity at inlet to the heater is 25 "m/s" , and at the outlet it is 30 "m/s" .
(a) Determine the specific enthalpy of the gas as it leaves the heater pipe, if the gas has a specific heat at constant pressure c_p= 0.844 "kJ/" ("kg K" ). 3
(b) Determine, using the steady flow energy equation, the heat added per kg of gas as it flows through the heater pipe.
Give your answer in "kJ/kg" .
An ideal gas enters a horizontal heating pipe at a temperature of 200oC, and with a specific enthalpy of 400 "kJ/ kg" .
As it travels along the pipe heat is added at constant pressure, and the air leaves the heater at a temperature of 300℃.
No work is done on the gas during the heating process.
The gas velocity at inlet to the heater is 25 "m/s" , and at the outlet it is 30 "m/s" .
(a) Determine the specific enthalpy of the gas as it leaves the heater pipe, if the gas has a specific heat at constant pressure c_p= 0.844 "kJ/" ("kg K" ). 3
(b) Determine, using the steady flow energy equation, the heat added per kg of gas as it flows through the heater pipe.
Give your answer in "kJ/kg" .
Mechanical Engineering
A rectangular steel plate is welded as a cantilever to a vertical column and supports a
single concentrated load 95, as shown in Figure 2. The material is ASTM A36 structural steel
and an E70xx welding electrode is used. The plate is 12 mm thickness. Determine the weld
size
single concentrated load 95, as shown in Figure 2. The material is ASTM A36 structural steel
and an E70xx welding electrode is used. The plate is 12 mm thickness. Determine the weld
size
Mechanical Engineering
Model equation for contaminant concentration in a space and apply to the following. A person breathes out CO2 at the rate of 0.3L/min. The concentration of CO2 in the incoming ventilation air is 400 ppm. It is desired to hold the concentration in the room below 1000ppm. Assuming that the air in the room is perfectly mixed, what is the minimum rate of air flow is required to maintain the desired level as per ASHRAE standard 62-1999?. If the same room is designed to occupy 6 persons determine the total amount of CO2 per second breath out and amount of incoming air to meet the ASHRAE standard 62-1999 desired comfortable ambient.
Mechanical Engineering
"In a reversible non-flow process with a gas, the initial pressure and specific volume are 270 psia and 4 cu. ft/lb, respectively. The final pressure and specific volume are 80 psia and 9 cu. ft/lb."
The same gas is brought reversibly from the same initial to the same final state above, but the state change is affected by a non-flow constant volume, and a non-flow constant pressure process in combination. Draw the p-v diagram and find the work done on or by the gas if he sequences of the processes is Constant pressure followed by constant volume
The same gas is brought reversibly from the same initial to the same final state above, but the state change is affected by a non-flow constant volume, and a non-flow constant pressure process in combination. Draw the p-v diagram and find the work done on or by the gas if he sequences of the processes is Constant pressure followed by constant volume
