This document describes a computational fluid dynamics (CFD) analysis of natural convection flow through a square cavity using ANSYS software. The study investigates laminar natural convection heat transfer in two-dimensional vertical air cavities for a range of Rayleigh numbers from 103 to 106 and an aspect ratio of 1. The geometry of the square cavity is created and meshed in ANSYS. Steady-state simulations are performed using the finite volume method. Boundary conditions of isothermal side walls and adiabatic top and bottom walls are applied. Contour plots and streamlines of velocity and temperature are analyzed to understand heat transfer trends. Nusselt number correlations as a function of Rayleigh number are proposed based