Report of FEM project

FE Analysis of Pressure Cooker ME 309a PROJECT

Group Members: Abhinaw Kumar Singh

:

2011183

Govinda Parasrampuria :

2011248

Jatin Gupta

2011052

:

Supervisors: Md. Zahid Ansari

April 24, 2014

Table of Contents Abstract ......................................................................................1 Analysis...................................................................................... 3 Objective ................................................................................... 9 Material Selection ................................................................... 10 Boundary Conditions .............................................................. 11 CAD Model............................................................................... 12 Design #1 ................................................................................ 12 Design #2................................................................................ 13 Design #3 ............................................................................... 14 Results ...................................................................................... 15 Conclusion .............................................................................. 16

Abstract In this project we have tried to analyze the stresses produced in a pressure cooker when subjected to above normal working conditions. After looking at a wide variety of possible shapes, sizes and materials, we arrived at a conclusion of choosing three designs and three materials, all subjected to various loads and analyzing them using FEM. We made use of commercial softwares like ANSYS, CATIA and ProEngineer to analyze the problem. We have looked at all the results of the analysis and have developed the detailed report for the same.

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Introduction  A common sight in every household is the pressure cooker.  Pressure cooking is the process of cooking food, using water or other cooking liquid, in a sealed vessel.  Pressure cookers heat food quickly because the internal steam pressure from the boiling liquid causes saturated steam (or "wet steam") to bombard and permeate the food. Thus, higher temperature water vapor (i.e., increased energy), which transfers heat more rapidly compared to dry air, cooks food very quickly.  Pressure is created initially by boiling a liquid such as water or broth inside the closed pressure cooker. The trapped steam increases the internal pressure and temperature.  After use, the pressure is slowly released so that the vessel can be safely opened.

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Analysis In our analysis of the problem the following figures were obtained 1. Design #1 a. Maximum Principal Stress

b. Maximum Shear Stress

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c. Total Deformation

d. Maximum Compressive Stress

2. Design #2 a. Maximum Principal Stress

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b. Maximum Shear Stress

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c. Total Deformation

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d. Maximum Compressive Stress

3. Design #3 a. Maximum Principal Stress

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b. Maximum Shear Stress c. Total Deformation

d. Maximum Compressive Stress

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Objective To obtain the data when a pressure cooking vessel is subjected to various degrees of varying loading, thermal and physical. Three types of materials used for the pressure cooker body were considered. To identify the best design out of the analyzed ones.

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Material Selection The three materials that we chose were: 1. Structural Steel 2. Stainless Steel 3. Aluminum Alloy

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Boundary Conditions Three types of boundary conditions have been chosen: 1. 2. 3.

Pressure = 100 kPa, T= 120°C Pressure = 150 kPa, T= 125°C Pressure = 200 kPa, T= 130°C

These boundary conditions have been so chosen so as to cover the case of above normal working conditions. These conditions will test the model under super-normal pressure and temperature loads.

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CAD Model DESIGN #1

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DESIGN #2

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DESIGN #3

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Results Results achieved: In all 3 designs, for given pressure and temperature conditions, cooker having aluminium alloy has maximum deformation and structural steel has the least.  Stainless Steel has maximum compressive stress for given conditions.  Maximum stress was observed at the centre of lid and rim of lid.

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Conclusion The ME 309a Project really helped a lot to get into the real world analysis process. We came to know how to model the problem in the software and look towards the subsequent design changes that can eliminate the cause of the problem. We faced several problems while making the CAD models and applying the various conditions to the model. In the future work might be done upon increasing the level of complexity and including various other loading and constraints in the system. We were assisted by Md. Zahid Ansari sir who guided us throughout the course of the project. It was a great experience with the group mates. We learned the concept used in the real world analysis process and overall it was a great experience.

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