Sound Generation of a Ceiling Fan (FW-H Vs. Wave Equation)

Description

Sound Generation of a Ceiling Fan in a Room, FW-H Vs. Wave Equation, Ansys Fluent CFD Simulation Training

In this project, the Sound Generation of a Ceiling Fan in a Room with both Ffowcs Williams and Hawkings and Wave equation models have been simulated. The simulation results have been investigated using ANSYS Fluent software. We perform this CFD project and investigate it by CFD analysis.

Acoustics is a science that deals with the study of mechanical waves in gases, liquids, and solids, including vibration, sound, ultrasound, and infrasound. It concerns production, control, transmission, reception, and sound effects.

The present model is designed in three dimensions using the Design Modeler software. The geometry of the solution is a 3D square shape domain with 4, 3, and 4 m in X, Y, and Z directions, respectively. The ceiling fans center is located at the center of the room and has a 2.7m.

This geometry has meshed in Ansys meshing software, and the total number of cells is 720783 for the first model and 534016 for the second one.

Also, due to the nature of the present problem, the transient solver has been used.

Sound Generation Methodology

This project investigates noise generation due to a ceiling fan in a room. There is a 3d square shape room with a fan in it. Also, two square windows are considered inlets and outlets in which wind blows inside by the incoming velocity of 3 m/s.

The problem is simulated in two ways; at first, the Integral Method by Ffowcs Williams and Hawkings is used in which the fan is rotating by the Mesh Motion method at 240 rpm. Some receiver points at different locations are defined in the domain.

Then in the second step, the ceiling fan is fixed without any motion while the wind blows inside the room with a 3m/s velocity. In this case, the noise generation due to the collision between wind and the fan is examined using a Method Based on the Wave Equation.

Sound Generation Conclusion

At the end of the solution process, two and three-dimensional contours and plots related to room pressure, temperature, and velocity are obtained. CFD Post software draws room sound pressure and amplitude plots in different points defined in Ansys Fluent software.

The temperature and velocity in the room are shown by 3d contour, and parameters related to generated noises are achieved both on the fan walls and the room environment.