Greenhouse Ventilation

Greenhouse Ventilation — ANSYS Fluent CFD Simulation

Description

This project simulates air ventilation inside a greenhouse using ANSYS Fluent, with particular attention to how internal fans and floor heating drive air circulation. A greenhouse must maintain the right temperature and air movement for the plants inside, and this is achieved through a combination of heating and fan-driven ventilation. The simulation captures how heat from the floor and airflow from the fans together set up the circulation that distributes warmth through the space. Within the Fan: Beginner CFD Training Package, this project applies fan-driven ventilation to a large enclosed space, combining fans, floor heating, convection, and radiation in a single case.

Methodology

The three-dimensional geometry — 10 m long, 3.15 m high, and 4 m wide — is built in SpaceClaim and meshed in ANSYS Meshing with 216,456 elements. Given the time-dependent nature of the circulation process, a transient solver is used throughout. Ventilation is driven by two small fans, each 5 cm in radius, rotating at 100 rad/s inside the greenhouse. The floor is heated with a fixed heat flux of 250 W/m², while the side walls exchange heat with the outside air through convection, defined by a heat-transfer coefficient of 30 W/m²K and a free-stream temperature of 300 K. A radiation model is also activated to capture radiative heat transfer alongside convection. Turbulence and temperature distribution are resolved using the realizable k-epsilon model together with the energy equation, and air density is allowed to follow the ideal-gas law so that the buoyancy effects from heating are captured rather than assumed away.

Analysis

The resulting velocity and temperature contours show the expected buoyancy-driven behavior: air near the greenhouse floor heats up and becomes less dense over time, while the surrounding cooler air, being denser, sinks and displaces it. This density difference sets up a natural circulation pattern, which the two fans reinforce and accelerate, sustaining a continuous cycle of heat transport through the greenhouse volume. From these results you can evaluate how effectively the fans and floor heating together ventilate and warm the greenhouse, and how the temperature and airflow distribute through the space. By the end of this project, you'll be able to set up a transient greenhouse-ventilation simulation combining fans, floor heating, convection, and radiation, apply the ideal-gas model to capture buoyancy, and interpret the velocity and temperature fields that describe the circulation sustaining a healthy growing environment.