This document serves as a comprehensive guide for using COMSOL Multiphysics software to perform various simulations, including structural mechanics, thermal analysis, and fluid dynamics. It details the setup and execution of simulations for a cantilever beam under point load, temperature variations in a workpiece, and fluid flow through a cylindrical tube. The guide provides step-by-step instructions for defining geometries, applying material properties, setting boundary conditions, and analyzing results. It is aimed at users familiar with finite element analysis and COMSOL's interface.