Isentropic Flow -Area Variation DOCX

Title	Isentropic Flow -Area Variation
Author	Chanteur Musique
Pages	10
File Size	55.9 KB
File Type	DOCX
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Isentropic Flow - Area Variation 13.1 Air is extracted from a large tank in which the temperature and pressure are 70 oC and 101 kPa (abs), respectively, through a nozzle. At one location in the nozzle the static pressure is 25 kPa and the diameter is 15 cm. What is the mass flow rate? Assume isentropic flow Answer: m=3.18 kg/s 13.3 Steam flows steadily and isentropically through a nozzle. At an upstream section where the speed is negligible, the temperature and pressure are 450 oC and 6 MPa (abs). At a section where the nozzle diameter is 2 cm, the steam pressure is 2 MPa (abs). Determine the speed and Mach number at this section and the mass flow rate of steam. Sketch the passage shape. Answer: V=781 m/s M=1.35 m=3.18 kg/s 13.5 Nitrogen flows through a diverging section of duct with A1=0.15 m2 and A2=0.45 m2 . If M1=1.7 and T1=30 oC, find M2 and T2. Answer: M=2.94 T = - 98 o C 13.7 At a section in a passage, the pressure is 30 psia, the temperature is 100 oF, and the speed is 1750 ft/s. At a section downstream the Mach number is 2.5. Determine the pressure at this downstream location for isentropic flow of air. Sketch the passage shape. Answer: p2 = 6.52 psi 13.8 Oxygen flows into an insulated duct with initial conditions of 200 kPa, 420 K, and 200 m/s. The area changes from A1 =0.6 m2 to A2=0.5 m2 . Compute M1, p01, and T01. Is this duct a nozzle or a diffuser? Calculate the exit conditions (pressure, temperature, and Mach number) provided that there are no losses. 13.9 Air is flowing in an adiabatic system at 20 lbm/s. At one section, the pressure is 30 psia, the temperature is 1200 oF, and the area is 8 in2 . At a downstream section, M2=1.2. Sketch the flow passage. Find the exit area provided the flow is reversible. Answer: Convergent duct A=1.016 in2 13.10 Air flows isentropically through a converging-diverging nozzle from a large tank containing air at 250 oC. At two locations where the area is 1 cm2 , the static pressures are 200 kPa and 50 kPa. Find the mass flow rate, the throat area, and the Mach numbers at the two locations. Computation...