Use of reverse engineering to create a realistic 3D model for CFD analysis of a control damper

Abstract

Accurate air flow measurements have been a highly sought-after discipline in the industry in recent years, especially among manufacturers of HVAC (Heating, Ventilation, and Air Conditioning) systems. One of the challenges for scientific research is the area of simulation and verification of results for sub-components of these systems, such as reducers, diffusers, or control dampers. Although these parts have a significant impact on measurements, they are often greatly simplified and or completely ignored in CAD models by HVAC manufacturers. As a result of this simplification, significant differences arise between laboratory measured results and CFD simulation results. However, to obtain realistic values from the simulation, it is necessary to use 3D data as close to reality as possible. This paper describes the process of creating a realistic model of a control damper that is part of the distribution box of the air ventilation system. This damper was 3D scanned using an ATOS II Triple Scan 5M and processed using GOM Professional. The dimensions of the duct and the angles between the end positions of the control damper were measured. Using reverse engineering in Geomagic Design X and the measured values, a sufficiently accurate 3D model of the control damper was created. The output data from reverse engineering was used as input data for CFD analysis. The CFD simulation of the control damper was performed for 3 different flow rates (10, 20, and 35 m3/h). Comparisons of simulation results between CAD data from the HVAC manufacturer and data from 3D scanning achieve a difference of up to 35 % (when the control damper is fully closed or partially open). Using a realistic 3D model of the control damper obtained by reverse engineering, the results and outputs of the simulation were significantly refined. The results of this work can be used in the design of distribution boxes or entire HVAC systems. © 2022 IEEE.