The Mechanical Engineering Department runs a course on Computer-Aided Engineering Design, ME 451/751. The course covers topics in Solid Modeling and its Applications in Engineering Design. The course as taught in the July-Dec Semester, 1997, had a heavy emphasis on the project component. Also, all project reports were submitted directly in the form of web pages so as to make this information available to others in the course. These reports are being released on the local network on an experimental basis, to recognize the immense effort put in by many of the project groups. Feedback is welcome.

Prizes were awarded to the [BEST PROJECT], and an honourable mention goes to the [BEST PRESENTATION].

Course Project Final Reports

1. CFD flow visualization
   Subrata Roy Choudhury and Shashank Sinha
   

   A visualization post-processor for a CFD program that outputs flow parameters such as pressure or temperature at different locations in a flow field. The input data may be 3-D or higher. Slices through the field are taken (currently manually) and interpolated to generate isobars and other contour lines, shaded profiles, etc. Sample displays are shown for flow across a delta winglet.
   

2. 2D Finite Element Mesh Generation
   Nishant K. Jha and Sharad Agrawal
   

   Generates a triangulation for Finite Element Analysis based on Delaunay Triangulation.
   

3. Configuration Space Obstacle Map as Union of Displaced polygons
   K. Santosh Kumar and V. Jeyakumar
   

   The configuration space map of non-convex polygons is difficult to determine. Here this is done as the union of several positions of the polygons.
   

4. Boolean operations between coupler curves and simple polygons
   Santosh Kulkarni and Anil Suryawanshi
   

   A tool attached to a coupler curve can be used to machine curved surfaces, or deposit material. This program performs boolean operations between coupler curves and polygons.
   

5. Synthesis of Linkage Mechanism using Genetic and Pattern Mathching Algorithms
   Shorya Awtar and Vipul K Gupta
   

   Given a desired coupler curve, attempts to determine an optimal four-bar linkage configuration that matches the given curve. Uses a slope vs. arc-length profle to characterize the curve and uses Genetic Algorithms in the parameter space of four-bar mechanisms to optimize the match. Commendable level of success in a very ambitious project.
   

   
6. 3-D CSG operations and mass property
   Sanjay Sharma and Rohit Grover [BEST PRESENTATION]

   Boolean constructs of 3D objects can be visualized by performing the boolean op's on the intercepts of the visual ray with each primitive. The same process can be used to efficiently compute the mass properties of boolean constructs. Primitives can be blocks or cylinders.
   

7. Graphic visualization of 3-D solids Ashish Kumar and Naveen Prakash
   

   Similar to above. Primitives can be blocks, cylinders, or spheres.

   
   
8. Orthographic Projection to wireframe
   Mohan Kishore and Amit Nagpal [BEST PROJECT]

   Based on a 2D drawing presented in the AutoCAD DXF format, generates a 3-D wireframe. Can be extended in the future to generate surface features based on the wireframe. Creates some edges which it is not possible to remove without considering aspects of 3-D topology (fig. on right below). Very robust, and with the potential to be directly useful, since DXF is also a standard interface for other programs. [Figure1] [Figure2]
   

9. NACA Airfoil section specifications
   Rakesh and Varun Agrawal

   Most practical aerofoil shapes can be represented in short using a four-digit or five-digit number according to a standard developed by the US Aeronautics organization (NACA>. This program provides a visualization tool showing the cross-section and also computes the pressure distribution on the upper and lower surfaces. Here are the contours of NACA 6612 and NACA 23012 foils.

   
   
10. Constraint based Assembly Analysis
    S Subramanyam and Suraj Gaurav
    

    Mechanisms can be defined as a set of constraints on points and lines on the various bodies constituting the mechanism. This program uses only this input to derive the input-output relations for lower and higher pairs. Results are shown for a slider-crank, a crank-lever 4-bar, and a lock-barrel (cam-follower).

11. 3D Surface Reconstruction from Point data
    Anoop Jayadevan and Sachin Maheswari

    How can one visualize form in a cluster of point data? "Alpha Shapes" define such an envelope for a set of points based on a ball-end stylus. As the ball increases in size, gaps cannot be entered into, and with an infinite radius ball the convex hull is obtained. This project extends this code from UIUC to perform point-data degradation - as the point-set comes to occupy significantly fewer points on the image, they are replaced by fewer and fewer points. The image on the right has about half the points of the initial data set. All these are drawin with an alpha size somewhat smaller than the hole in the torus.

    
    
12. Nesting of 2D Polygonal Parts using a Shape Reasoning Heuristic
    Anup and Saurabh Shrivastava

    In cutting cloth for apparel or punching out blanks from a steel sheet, one needs to squeeze or "nest" the items as densely as possible. This program uses surface features to pack different polygon-types into a given space.
    

13. Layered Rapid Prototyping by Solid Ground Curing
    D. Venkateswarlu, N. Chandrasekhar V. Rao, K. Sridhar

    A part (a pump casing from Kirloskar) is developed for Rapid Prototyping using the Pro/Engineer package. Contains a description of the Solid Ground Curing Process and a view of the part itself.
    

14. Rapid Prototyping by Fused Deposition Modeling
    Amit Nema, Sandeep Gupta, and Asit Aggarwal
    

    Another pump housing is developed using the Pro/Engineer package; this time there is a description of the Fused Deposition Modeling (FDM) Process.
    

    
15. 2-1/2-D Prismatic Solid Modeler
    Rishabh Misra and Manish Kumar
    

    You build projective solids by extruding from the ground up. An excellent interface, but the geometry is limited to objects whose projective axes are all aligned.
    

16. Development of a X windows Library for Curves and Surfaces
    Saikat Sen
    

    An interactive library for bezier, B-spline curves, and bilinear/lofted/ Coon's surfaces, with an introduction to NURB curves.
    

17. Animation and contact analysis of meshed gears - Yogesh / Shamshette / Ganesh [Report Not Available]