An investigation of the indoor environment and its influence on manufacturing applications via computational fluid dynamics simulation

The prevalence of precision manufacturing equipment in industrial facilities continues increasing with advances in manufacturing science and technology. However, challenges with the built environment for manufacturing applications are becoming more apparent. For example, traditional heating, ventilation, and air conditioning (HVAC) systems cannot accurately detect environmental changes in large manufacturing spaces. This results in the untimely activation of the HVAC system and, subsequently, wasted energy, which is not conducive to sustainable development. Accordingly, a new approach is needed that can accurately monitor environmental variations around equipment to change the indoor environment with improved efficiency. This research uses computational fluid dynamics (CFD) to simulate the ambient conditions of a manufacturing environment during computer numerical control (CNC) machining scenarios under varied conditions: manned vs. unmanned operations, machining vs. no machining, and an open vs. closed door. The simulations were validated with sensor data, resulting in an average error of 0.1% and an error range of 0 m/s to 0.65 m/s for the temperature and airflow simulations, respectively. The opening of the laboratory door led to the largest change in ambient conditions with an increase in temperature of 3.81K (vs. the closed-door scenario). Under these conditions, the associated thermal deformation in the machine tool frame was estimated to reach up to 0.085 mm, which adversely affects the range of precision CNC machining tolerances (+/- 0.05 mm). Future research is recommended to scale-up the simulations to a factory to inform production scheduling for precision manufacturing in order to reduce the load on the HVAC system.