Heat Distribution Simulation using Pthreads

This repository contains a C program designed to simulate heat distribution across a 2D grid. The simulation is parallelized using POSIX threads (pthreads) to enhance performance and demonstrate the application of multithreading in computational physics problems.

Problem Description

The program models the temporal evolution of heat distribution on a 2D grid, representing a simplified scenario of heat conduction in a square plate. The simulation uses a finite difference method to approximate the heat equation, with specific initial and boundary conditions.

Initial and Boundary Conditions

• Grid Size: The computational domain is a 2D grid of size 1000 x 1000 points.
• Initial Temperature Distribution:
  • All points within the central region defined by coordinates (200, 200) to (800, 800) are initialized to 500 degrees.
  • The temperature of all other points is set to zero.
• Boundary Conditions: Points on the boundary of the grid maintain a constant temperature of zero throughout the simulation.

Simulation Parameters

• Temperature Update Rule: The temperature of a point at timestep t is computed based on its temperature and the temperatures of its immediate neighbors at timestep t-1, according to the formula: T(x,y)(t) = T(x,y)(t-1) + Cx * (T(x+1,y)(t-1) + T(x-1,y)(t-1) – 2 * T(x,y)(t-1)) + Cy * (T(x,y+1)(t-1) + T(x,y-1)(t-1) – 2 * T(x,y)(t-1))

Where Cx and Cy are constants that govern the rate of heat transfer along the x and y axes, respectively.

• Time Steps: The simulation progresses through 4000 time steps.
• Reporting: After every 200 time steps, the program prints the temperatures at specific grid points: (1, 1), (150,150), (400, 400), (500, 500), (750, 750), and (900,900).

Implementation Details

The program is implemented in C and utilizes pthreads to divide the computation across multiple processors, aiming for a high degree of parallel speedup. A barrier synchronization mechanism ensures that all threads have completed their calculations at each timestep before proceeding to the next, maintaining data consistency.

Building and Running

To compile the program, use:

cc -lpthread -lrt TempGrid_HW3.c -o TempGrid_HW3

To run the compiled binary, specifying the number of threads:

./bin/HW3_updated <num_threads>

To run in batch more, comparing the performance of with different cores, you can execute the perl script below:

./automate/batch_run.pl

Output

The program outputs the temperatures of specified grid points after every 200 timesteps and displays the total runtime in nanoseconds and seconds.

License

This project is open-sourced under the MIT License.