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CHE323 TRANSPORT PHENOMENA II

COMPRESSIBLE FLOW IN NOZZLE AND ORIFICE

QUESTIONS

1 At a given cross section of a nozzle the air velocity is 60m/s  while

the pressure and temperature are 800kPa   and 450 K 

respectively. Calculate the reservoir’s pressure, temperature and

density.

2 At a point in an isentropic uid stream, the Mach numer is 2 . !f 

the reservoir conditions are 7atmospheres  and 400 K  , calculate a"

the conditions at the given point and " the mass ow rate per unit

cross sectional area.

# $as ows through a converging nozzle of throat diameter 0.15m

from a reservoir at a pressure of 5kPa   and a temperature of 

300 K  . %etermine the ma&imum ow rate and the conditions at

the throat if the ow is 'ust sonic there.( )he ratio of mass ow rate per unit cross sectional area for a given

air ow to that at sonic velocity is 0.5 . %etermine the value of 

Mach numer.

* A converging nozzle with straight sides has diameters 0.3m   and

0.15m   at the inlet and e&it respectively and it is 0.6m   long.

%etermine the velocity of ow midway etween the ends if  Ma  is

0.3  at the e&it.

+ Air owing from a reservoir at 6.5kPa   and 400 K    through a

converging nozzle is reuired at a Mach numer of 0.7 . Calculate

the e&it conditions.

- Air ows out of a converging nozzle at a Mach numer of 0.8 . )he e&it

diameter of the nozzle is 180mm . hat is the ow velocity in terms of 

Mach numer at a point upstream of the e&it where the ow area is twice

that of the e&it.

/ )he throat diameter of a converging nozzle is 100mm . )he owing uid

is air and the nozzle is 'ust cho0ed. hat is the Mach numer at the ase

of the nozzle where the diameter is 250mm .

Air ows from a reservoir at 1 atmospheres pressure and * 3 

temperature to another reservoir at / atmospheres pressure through a

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converging nozzle of * mm throat diameter. !f the two reservoir pressures

remain constant, determine the mass ow rate. !f the ac0 pressure is

decreased in order to increase the ow rate, what is the limiting ac0

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