Convergent Nozzle

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A nozzle is a device designed to control the direction or characteristics of a fluid flow (especially to increase velocity) as it exits (or enter) an enclosed chamber or pipe via orifice. A numerical study has been carried out to analyse the performance and flow characteristics of the convergent-divergent nozzle under various operating pressure ratio and with different nozzle profiles, also to determine the location and strength of the normal shock in the divergent portion of the nozzle .Various flow parameters across the normal shock had been obtained by using gas table.

Keywords: Mach number, Sub-sonic, Super-sonic, Sonic, Compressible flow, Throat.

1. Introduction
A de Laval nozzle (or convergent-divergent nozzle, CD nozzle or con-di nozzle) is a tube that is pinched in the middle, making an hourglass-shape. It is used as a …show more content…

Components/Materials used
Air Compressor
Plumbing setup consisting of CI pipes of various sizes
Convergent nozzle which is interchangeable, profiled and polished brass nozzle
Convergent-Divergent nozzle
Pressure dial gauges
Chock valves
Screws, nuts, bolts, washer
Teflon tape

4. Methodology
Let us consider a convergent divergent nozzle with inlet and outlet section specified in the diagram as 1 and 5 respectively. In the diagram shown below section 2 represent the throat i.e, the maximum mass flow rate, Section 3 and 4 represents the flow conditions before and after the shock respectively.

Figure 3 C-D Nozzle
5. Working of Nozzle system
The compressed air from the compressor is passed through the inlet of the nozzle where the compressed air converges, then it is passed through the throat where the air compresses because of small cross-sectional area here the pressure decreases, then it is passed through the diverging part of the nozzle where the velocity increases.
6. Observation table of C-D nozzle

7. Calculations
Sample calculation for CD nozzle- first reading (P2=4.9 bar)
T=32=305 K
P =1.013 bar
P2= 4.9

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