Question

Question 5 Soalan 5 (a) Helium enters a nozzle at 0.6 MPa, 590 K, and a velocity of 120 m/s. Assume the flow is isentropic. The properties of helium are R 2.0769 k/kg-K, c, = 5.1926 k/kg K, and k-1.667 [Helium memasuki muneung pada 0.6 MPa 590 K, dan halaju 120 m/s. Andaikan aliran adalah seentropi Sifat helium adalah R- 2.0769 kJ/kg K, c- 5.1926 kJhg-K, and k- 1.667.] Calculate the stagnation pressure and temperature in the nozzle. [Kira tekanan genangan dan suhu dalam muncung] (4 Marks/Markah) (iDetermine the pressure and temperature of helium at a location where the velocity equals the speed of sound. Tentukan tekanan dan suhu helium di tempat yang halajunya sama dengan kelajuan bunyi (4 Marks/Markah) (iii Determine the speed of sound and the Mach number at the nozzle inlet. Tentukan kelajuan burgi dan nombor Mach di bahagian masuk muncung ] (5 Marks/Markah) (iv) Calculate the ratio of area at location in Question 5(a)(i) to the entrance area. [Kira nisbah kawasan di lokasi dalam Soalan 5(a)) ke kawasan pintu manuk (4 Marks/Markah) (b) If the entrance velocity is neglected, calculate the ratio of area at a location where the velocity equals the speed of sound and compare it with what obtained in Question 5(a)(iii) Jika halaju alur masuk diabaikan, kira nisbah kawasan di tempat yang halajunya halaju bunyi dan bandingkan dengan apayang didapati dalam Soalan 5(a) (i) asama dengan (8 Marks/Markah) ooO00-

Answer 1

UNIRANK VE 120 T-SJ0 Nozzle for he lium R- R 2.076J KJ rg R i) T+ v2 T = )20 Sgo t 2 x S.1926* fo au Sg1. 3&658 K K/K To 1.60.66 59/.3& Sgo O.6035 mfa V a when Ktl. 2 2.667 2 2 T: 786 K dk I.231 mP

UNIRANK Now velocity of forhelium Sorun d RRT 66tx 2076.9 x S90 a = 14 29.22 8 m/s Va mach /2 0 No. 029. 22& = u 0.083J6 Area aatio A, hiK-I) 2(K-) K-I 2 A (2.66# 2 Co.66# 2664 2 C0.664 2 O.a 83J6 /.667t .S24 2032) O.0833 G 87.1952 A 37. 1952