Solar Chimney

Solar Chimney — ANSYS Fluent CFD Simulation

Description

Welcome to the Solar Chimney CFD Simulation module. This project offers an in-depth study of buoyancy-driven flows, applying Computational Fluid Dynamics in ANSYS Fluent to analyze and optimize solar chimneys through a heat-transfer lens that couples conduction, convection, and radiation. A solar chimney is a passive ventilation technology: solar energy absorbed at the chimney surfaces heats the adjacent air, and the resulting buoyancy — the stack effect — sets the air in motion and drives natural ventilation without any mechanical fan. The essential components of an effective system are the solar collector, the air channel, and the outlet. This module explores how the technology works and how CFD can be used to improve its thermal efficiency in sustainable building design. Within the Heat Transfer package, it combines radiation with buoyancy-driven convection, building on earlier natural-convection cases toward a coupled passive-ventilation problem.

Methodology

The CFD setup in ANSYS Fluent begins with a meshing strategy that resolves both the large-scale chimney structure and the fine detail of the airflow channels, followed by the selection and configuration of appropriate turbulence, heat-transfer, and buoyancy models for an accurate solution. Particular attention is given to the boundary conditions that capture the buoyancy effect realistically: the solar energy absorbed at the chimney surfaces is represented as the surface heating that drives the buoyant flow, and the atmospheric conditions and pressure differentials needed to reproduce natural ventilation are defined. Because the flow is thermally induced and buoyancy-driven, the models are chosen to suit natural convection rather than forced flow. The setup also supports a parametric approach, allowing solar radiation to be varied and the chimney to be simulated under different diurnal and seasonal conditions.

Analysis

The key outputs of the simulation are temperature contours, which reveal the thermal stratification and heat distribution within the chimney, and velocity vector fields, which show how effectively the buoyancy-driven ventilation performs. Linking solar input directly to chimney performance, a parametric study quantifies how variations in solar radiation influence flow rates and temperature fields, and simulations under different times of day and seasons assess how performance shifts throughout the year. These results translate into practical design improvements: ventilation rates and thermal efficiency can be compared across configurations, and the data used to refine key parameters such as chimney height, width, and inclination angle. By the end of the project, you will be able to set up and run complete solar chimney simulations in ANSYS Fluent, interpret the results to evaluate ventilation performance and identify improvements, and apply those insights to real engineering challenges — from integrating solar chimneys into eco-friendly architecture to improving natural ventilation in industrial facilities and large structures.