Question

SULIT (ENT247) (b) Air flows from a reservoir at 20°C and 200 kPa through a 5 cm-diameter throat and exits from a 10-cm-diameter nozzle as shown in Figure 5. A normal shock wave located at a position of the diameter is 7.5 cm. Assume y = 1,4 and R-287 J/kg.K Udara mengalir dari kawas an tadahan pada 20°C dan 200 kPa melalui nosel dengan leheran 5 cm diameter dan keluaran pada 10 cm diameter seperti diturjukkan dalam Gambarajah 5. Satu kejutan normal terletak pada kedudukan diameter adalah 7.5 cm. Anggap y= 1.4 de R-287 Jkg K. dan d7.5 cm der5 cm Exit de 10 cm Shock wave Figure 5 Gambarajah 5] Calculate the Mach number on region (1) Mai, Mach number on region (2) Maz, and stagnation pressure on region (2) P. [Kirakan nombor Mac pada kawasan (1) Mas, nombor Mac pada kawasan (2) Ma dan tekanan genang an pada kawasan (2) P (i) (5 Marks/Markah) (i Determine the exit mach number Mae and exit pressure Pe Tentukan nombor Mac pada keluaran Ma, dan tekanan kehuaran P.] (5 Marks/Markah)

Answer 1

dsh = 5cm Ve 2. 'exit dezik= locm di) Shock Ware We need to MaMa Ma, amd Pe 1. R28+ 5|ug k and To,=20 293K Pa o kPa (du) dsh Ash (4.5 5

= 2 25 From rentrofi o tnbo see = W we uik An Ma = a.33 m Nrmal hock table, at 2.33 g Maz0.531 we o. 5o5 amd alos Poz Po Ma2.33 Pozo.5 o 15 x 200 KPa Poz14.03 KPa

NO auao he phock MA=0.531,m Juntrfpic Agh A*Maz 286 Bous tabls To Calcurate Ma,, we need Ae Are Ae/A At X Atz Ae AL2 AsM/An x 1.286 (denitt 2.25 lo/51286 2.25

2.286 Neo Mac at Ae -2.2886 can Avz be calaulated fome ipdrofic Na= 2.345 Nou Pe Poz Mae- 2.345 (fropn isentropie flor Aableo Pe20.741X 4.03 KPa Pe 84.496 KPa