Computational and Investigational Proportional Flow Study on Cd Nozzle

As part of our study , we had to design, produce, and test a convergent-divergent type nozzle with a specific area ratio. The goal of this project is to replicate the operation of a converging-diverging nozzle, which is possibly the most significant and fundamental piece of engineering hardware involved with propulsion and high-speed gas flow.For this, we first examined a specific area ratio. Three distinct designs are constructed for the given area ratio (convergent, divergent, and convergent divergent).The flow through the nozzle is analysed under various back pressure situations. Then, using the values obtained from the analysis, we constructed the nozzle and evaluated its operation. We also tested the choke conditions under varied back pressures and the mass flow rate that corresponds to it. Finally, we plotted the curve of mass flow rates vs. pressure distribution with practical values. Thus, with the assistance of our department faculty, we successfully accomplished this assignment.


Fig 1-convergent-divergent nozzle
A Convergent-Divergent nozzle has a cross section that reduces from the input section to the throat and then increases from the throat to the outlet region.To generate supersonic flow, a divergent-convergent nozzle is used.Because it produces supersonic flow, it is also known as a De Laval nozzle.The C-D Nozzle is linked to a compressor equipped with an inlet temperature and pressure gauge, as well as a regulating valve that regulates the amount of inlet pressure and temperature.A pipe connects the compressor, nozzle pressure, and temperature gauges.
Using a digital pressure transducer, 7 pressure tapings are put into the nozzle to determine pressure fluctuations.In this case, three tapings are placed in a convergent part, one in the throat, and the remaining three in the divergent section.The exit part additionally has a temperature and pressure gauge as well as regulating valves.

SOFTWARE AND HARDWARE REQUIREMENT
➢ CATIA (for design) ➢ NASTRAN (for structural analysis) ➢ CFD (fluent for flow)

CATIA V5R20
CATIA is a powerful programme for creating rich and complicated designs.It is also software for mechanical design.It is a set of feature-based, parametric solid modelling design tools that make use of the simple Windows graphical user interface.We may develop completely associative 3D solid models with or without constraints, while capturing the design purpose with automatic or user-defined relations.CATIA V5R20 is the most recent version of the software.CATIA V5 provides three platforms.

CATIA V5 P1
Users benefit from PLM Productivity at a low cost and with the assurance of future expansion.Based on CATIA V5 product design-in-context, product knowledge reuse, end-to-end associability, product validation, and collaborative change management capabilities, they may do associative product engineering.
CATIA V5 P2 Knowledge integration, process accelerators, and customised tools can help users optimise their PLM operations.

CATIA V5 P3
Users may get the most out of advanced procedures by focusing on specific solutions.They may lead expert engineering and advanced innovation by leveraging unique and highly specialised applications that combine product and process expertise.

CFD
ANSYS CFD is a more advanced version of ANSYS.CFD has been the industry standard for the computer-aided analysis of stress, vibration, structural failure/durability, heat transfer, noise/acoustics, and flutter/aero elasticity in every major industry, including aerospace, defence, automotive, shipbuilding, heavy machinery, medical, and consumer products.It is used for fluent analysis and is simple to use.

NOZZLE DISCRIPTION: Fig 2: Nozzle description
The nozzle's overall length is 300mm (3m).From the entrance to the throat, the distance is 150mm.The throat measures 15mm in diameter.The nozzle has been separated into seven pieces and pressure tapings have been installed.The distance between each pressure tape is now 30mm, and the diameter has grown by 3mm.We separated the nozzle into seven pieces to accommodate the pressure tapings, and the holes were drilled perpendicular to the nozzle surface.The hole's diameter is 5mm.

STEPS:
1. Draw a nozzle using "CATIA" 2. Open "NASTRAN" then click advance stimulation, do right click then change Fem Stimulation, Change analyze type as structure.3. Change SIM file to FEM file.4. For applying material, initially select the object .Go to mesh collector click material apply.Select the material as stainless steel and click O.k. 5.For meshing the object click 3D mesh, change the element as size 20.Then select the object to be meshed, finally click O.K. 6. Change FEM file to SIM file.7. Click the option Load type ,select pressure, at that time a dialogue box will be opened in that click select object then select the portion where pressure has to be applied then click O.K.After completing this dialogue box will be opened, type the required pressure (N/mm).We have given the pressure limit from 0-6.5 bar.Still 6.5bar there was no major fracture if exceeded the limit fracture will occur.
The following figures are obtained from the results of the above CFD process.

COMPUTATIONAL RESULTS
We have designed a nozzle using "CATIA" software and then we have analyzed it using "FLUENT" software.The following results are given below.

Nozzle length v/s X-coordinate velocity
Series1

CONCLUSION:
This project assists in visualising the flow through this type of nozzle under a variety of conditions.We gave a chosen area ratio for our nozzle design, i.e. the throat diameter (15mm), and then compared the CFD and experimental findings to determine that our nozzle can tolerate a pressure of 6.5 bar.We've attained supersonic flow.The supersonic flow has a range of 2.0 Mach number.As a result, our analyses in both NASTRAN and CFD software were successful.Our model is not a failure model, and it can sustain a pressure range of 6.5 bar, allowing it to be used in a variety of applications.