COMPUTATIONAL FLUID DYNAMICS MODELED AIR SPEED THROUGH IN-SHELL PEANUTS IN DRYING WAGONS COMPARED TO MEASURED AIR SPEED

Abstract

Abstract.HighlightsPeanut drying wagon internal airflow simulation and visualization.Comparison of computer fluid dynamic (CFD) solutions to measured air speed.Modeling of airflow through masses of in-shell peanuts. Information is lacking about airflow through masses of drying in-shell peanuts in drying wagons because of the difficulties encountered in making direct measurements. Information about airflow is needed to improve efficiency of drying peanuts to make peanut crops more profitable. Computational Fluid Dynamics (CFD) modeled airflow through in-shell peanuts loaded in drying wagons was validated using actual airflow measurements. CFD models allow for the investigation of airflow within peanut loads and the air plenum of drying wagons. Airflow through a wagon load of in-shell peanuts treated as a solid mass with distributed resistance was modeled using airflow behavior following Darcy’s law. CFD model simulations were undertaken using measured air speed, wagon air plenum static air pressure, and fan performance curve data. CFD modeling was based on actual air speed measurements made at 40 locations on the top surface of wagon loads of in-shell peanuts. The 40 measurement locations represented the top center of 40 blocks which the peanut load was divided into to investigate air speed. To match actual measurements to CFD model results, CFD models were configured with the same 40 blocks as those of the actual measurements. In CFD models, the permeability of the peanuts in each of the 40 blocks could be varied in a trial-and-error fashion to increase or decrease the air speed at the top surface of the peanut load to match that of the actual air speed measured for each of the blocks. Model results reproduced the measured air speed to within the accuracy limits of the air speed measurements. The air speed and static air pressure distribution in the wagon air plenum was found not to be uniform even when all blocks had the same permeability. Model results revealed wagon air plenum air speed patterns and static air pressure distribution could explain the general air speed distribution of slower air speeds at the top surface of the peanut load near the wagon air inlet wall and the increasing air speed along the length of the wagon. Permeability variations within the peanut load were found to explain localized variations in air speed at the top surface of the peanut load. Keywords: Air speed, Airflow, Modeled results compared to measured, Computational fluid dynamics modeling, Drying wagon, In-shell Peanuts, Peanut bulk permeability, Peanut curing, Peanut drying .