Discipline: Technology and Engineering
Subcategory: Civil/Mechanical/Manufacturing Engineering
Ossie R. T. Douglas - University of South Florida
Computational fluid dynamics (CFD) analysis of thermal airflow distribution in a small scale fabric dryer. Following industrial fabric drying techniques, the fabric dryer is controlled at constant temperatures within the enclosure and a CFD model developed. It is validated using experimental data obtained from fabric dryer prototype. The CFD analysis results display that careful selection of the flow model, in addition to the simplified boundary conditions, give approximate temperature predictions throughout the fabric dryer. The CFD model is used to predict the flow and thermal fields within the dryer and to show how key features, such as regions of recirculating flow, depend on the speeds of the air flow at the inlet.
Constant temperature distribution maintained at the outlet is an important design goal of the fabric dryer. Tubular heating elements were used to generate heat within fabric dryer. Thermometers were used to measure the temperature of the inlet, outlet, and interior of the fabric dryer. Using thermocouples, the temperature of the tubular heating elements were measured to calculate conductive heat flux. Air flow was measured at the inlet of the fabric dryer, using an anemometer. A model of the interior air flow was developed, using ANSYS FLUENT CFD software. The insulated boundary conditions were used for all walls expect the inlet, outlet, and bottom facing wall of the fabric dryer mesh. The velocity of air that was applied to the inlet ranged between 0.1m/s 1 m/s. Atmospheric air pressure was applied at the outlet. A heat flux was applied to the bottom facing wall of the dryer representing the total heat flux generated by the tubular heat elements. The simulation displayed constant temperature distribution approaching the outlet of the fabric dryer. The results provide information on magnitude of air flow that can be used to determine the effects of air flow below 0.1 m/s within a fabric dryer. Future work stemming from this investigation will include the modelling of a similar enclosure, with the inclusion of fabric wetted with water. The model will be used to determine the appropriate values necessary to apply to the feed path of the fabric through the dryer.
References: Khatir, Z., et al. ‘Computational Fluid Dynamics (CFD) Investigation of Air Flow and Temperature Distribution in a Small Scale Bread-Baking Oven.’ Applied Energy, vol. 89, no. 1, 2012, pp. 89-96. SCOPUS, www.scopus.com, doi:10.1016/j.apenergy.2011.02.002.
Chua, K. J., et al. ‘Modelling the Moisture and Temperature Distribution within an Agricultural Product Undergoing Time-Varying Drying Schemes.’ Biosystems Engineering, vol. 81, no. 1, 2002, pp. 99-111. SCOPUS, www.scopus.com, doi:10.1006/bioe.2001.0026.
Funder Acknowledgement(s): I would like to thank C. Wickranarathe for simulation support. I also thank J. Dhau and P. Myers at Molekule for additional support. Funding was provided by an NSF/LSAMP grant to B. Batson.
Faculty Advisor: D. Yogi Goswami, firstname.lastname@example.org
Role: I developed the model for simulation within ANSYS FLUENT Computational Fluent Dynamics (CFD) software. In addition, gathered data for input for developing boundary conditions for model.