Indoor Climate Analysis: Room Heating and Natural Ventilation CFD Study Using ANSYS Fluent

Project Overview

This computational study analyzes indoor airflow dynamics and thermal behavior within a heated room utilizing natural single-sided ventilation through ANSYS Fluent simulation. The investigation features an aluminum heating radiator producing 23,469 W/m³ of thermal output as the primary heat source. A side-mounted window serves as the natural ventilation outlet, operating under ambient atmospheric pressure with backflow temperatures matching interior conditions. The research aims to characterize the complex airflow patterns and thermal distribution within this naturally ventilated heated space.

Model Geometry and Computational Grid

The three-dimensional room model was constructed using Design Modeler, featuring interior dimensions of 2.15m × 2.16m × 3.32m. A rectangular heating unit is strategically positioned along the base of one sidewall to represent typical residential heating configurations.

The computational grid was developed using ANSYS Meshing with an unstructured mesh topology comprising 987,087 computational cells, providing sufficient resolution for accurate flow and thermal boundary layer capture.

CFD Analysis Setup

The numerical simulation employs the following modeling framework:

Core Assumptions:

• Pressure-based flow solver
• Combined fluid dynamics and thermal analysis
• Steady-state operating conditions
• Gravitational effects included (9.81 m/s²)

Turbulence Framework:

• Realizable k-epsilon turbulence model
• Standard wall function approach

Boundary Specifications:

• Window: Pressure outlet at atmospheric conditions
• Room surfaces: Stationary walls with zero heat flux
• Radiator: Volumetric heat generation source

Numerical Approach:

• SIMPLE algorithm for pressure-velocity coupling
• High-order discretization schemes for improved accuracy
• Standard initialization at atmospheric conditions (101,325 Pa, 300 K)

Simulation Results and Visualization

The computational analysis generates comprehensive flow and thermal field data, including detailed pressure, temperature, and velocity distributions in both 2D and 3D formats. Velocity vector fields provide insight into circulation patterns. Cross-sectional analysis is conducted on XY and YZ planes, with multiple YZ sections examined to fully characterize the three-dimensional nature of the heated room’s airflow and thermal behavior.