In: Physics
1.A steel tube carries gasoline (?= 751 kg/m3) at an average velocity of 2.05 m/s. If the inside diameter of the tube is 1.27 inches, find the volume flow rate and the mass flow rate.
2.Two streams, a cold stream and a hot stream, enter a mixing chamber where both streams combine and exit through a single tube. The mass flow rate of the hot stream is 5 kg/s, and the inside diameter of the tube carrying the cold stream is 3 cm. Find the mass flow rate of the cold stream required to produce an exit velocity of 8 m/s in a tube with an inside diameter of 4.5 cm. Take density as 1000 kg/m3 if necessary.
3.A ventilation duct supplies fresh filtered air to a clean room where semiconductor devices are manufactured. The cross section of the filter is 1.2 m × 1.6 m. If the volume flow rate of air to the clean room is 3 m3/s, find the average velocity of the air as it passes through the filter. If ? = 1.194 kg/m3 for the air, find the mass flow rate.
4.A nozzle is a device that accelerates the flow of a fluid. A circular nozzle that converges from an inside diameter of 25 cm to 15 cm carries a gas at 45 gal/min. Find the change in average velocity of the gas.
1 )
= 751 kg/m3
V = average velocity = 2.05 m/s
d = diameter of the tube is 1.27 inches = 0.0322 m
r = 0.0161 m
A = 3.14 X 0.01612 = 8.13 X 10-4 m2
Mflow rate = the mass flow rate = ?
the volume flow rate = Vflowrate
Mflow rate = V A
= 751 X 2.05 X 8.13 X 10-4
Mflow rate = 1.251 kg/sec
Mflowrate = Vflow rate
1.251 / 751 = Vflow rate
Vflowrate = 1.665 X 10-3 m3/sec
2 )
V = 8 m/s
d = 4.5 cm
r = 2.25 cm = 0.0225 m
A = 3.14 X 0.02252
= 1000 kg/m3
Mflow rate = V A
Mflow rate = 1000 X 8 X 3.14 X 0.02252
Mflow rate = 12.717 kg/sec
3 )
A = 1.2 m X 1.6 m
Vflowrate = 3 m3/s
= 1.194 kg/m3 for the air,
find the mass flow rate.
Mflowrate = Vflow rate
Mflowrate = 1.194 X 3
Mflowrate = 3.582 kg/sec
4 )
Vflow rate = A V
Vflow rate = 45 gal/min = 0.00283 m3/sec
V = Vflow rate / A
V = 0.00283 / 3.14 X ( 0.1252 - 0.0752 )
V = 0.090127 m/s