{"id":396375,"date":"2024-12-05T06:22:45","date_gmt":"2024-12-05T06:22:45","guid":{"rendered":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/working-on-dryer-operating-from-solar-load-help-needed\/"},"modified":"2025-08-21T08:16:39","modified_gmt":"2025-08-21T08:16:39","slug":"working-on-dryer-operating-from-solar-load-help-needed","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/working-on-dryer-operating-from-solar-load-help-needed\/","title":{"rendered":"Working on dryer operating from Solar Load. Help needed!"},"content":{"rendered":"

<p>Hey everybody! I am working on a heat flow CFD model for a solar crop dryer that will be deployed and tested in Guatemala. The basic operation of the dryer is a large tube of transparent plastic is inflated by air blown from a fan. This air that then fills the volume within the dryer, which is heated from solar radiation and passed over corn kernels to dry them. We are less so interested in fully modeling the entire system (with the corn included), and more so interested in learning about the energy transferred to the fluid volume (the inside of the dryer). To represent the dryer volume for the simulation, I have created a very thin-walled ‘shell’ that represents the overall shape of the plastic enclosure\/bubble we are going to be creating. The hole at the front is for a fan, which will blow air towards the rectangular side, which is going to be held in shape by a frame and an active vent placed there to release pressure and heat.<\/p><p><\/p><p style=”text-align: center;”><span style=”font-size: 12pt;”>Dryer outer structure<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”>In Fluent, I have created a valid volume mesh for the inner fluid region, and created boundary conditions for the fan inlet and the pressure outlet (I should be able to adjust the pressure to emulate the active vent changing the outlet pressure on the real dryer). Below is the mesh as it is visible in Fluent:<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”><\/span><\/p><p style=”text-align: center;”><span style=”font-size: 12pt;”>Fluent mesh with flow in\/out BCs<\/span><\/p><p style=”text-align: left;”> <\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”>In fluent, I have the Viscous SST k-omega enabled and Radiation enabled. Please let me know if I need to change anything in these panels, or if my radiation model needs to be set to a specific one (setting model to “Off” didn’t seem to fail, but it could very well be what i need to change):<\/span><\/p><p style=”text-align: center;”><span style=”font-size: 14pt;”><\/span><\/p><p style=”text-align: center;”>Viscous settings<\/p><p style=”text-align: center;”><\/p><p style=”text-align: center;”><span style=”font-size: 12pt;”>Radiation settings<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”>In Radiation, I have enabled Solar loading with Solar Ray Tracing enabled, using Solar position and time dta to simulate the dryer in Guatemala around mid-day. here are my Solar Calculator settings, and the console printout:<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”><\/span><\/p><p style=”text-align: center;”><span style=”font-size: 12pt;”>Solar calculator settings<\/span><\/p><p style=”text-align: center;”><span style=”font-size: 12pt;”><\/span><\/p><p style=”text-align: center;”><span style=”font-size: 12pt;”>Solar Calculator Values<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”>Do I need to adjust the sunshine factor or the XYZ\/North-East positioning, or can I leave those alone?<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”>for Boundary Conditions, I also need some guidance. I have successfully set the inlet and outlet BCs and the interior fluid volume conditions are all set. But the exterior wall is where I am struggling. I assume we want a Radiation wall, to participate in Solar Ray Tracing? Should I use the ‘Radiation’ option on Thermal wall BC? Should I use Heat Flux? Here is what I have set now. I would also like to know how to find material settings for specific plastics or what values I should set here for Absorpivity and Transmissivity, or if I can leave them be.<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”><\/span><\/p><p style=”text-align: center;”><span style=”font-size: 12pt;”>Radiation Wall BC<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”>For reporting, I want to know the radiation heat transfer rate, or more specifically how much heat energy is transferred to the air via solar radiation. I know for a fact I am setting this up wrong, as the values I get are all over the place or sometimes just stuck at zero. Here is the panel for my report definition:<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”><\/span><\/p><p style=”text-align: center;”><span style=”font-size: 12pt;”>Report definitions settings – please help<\/span><\/p><p style=”text-align: left;”><span style=”font-size: 14pt;”>Or if you know a better way to get readable\/understandable results please let me know. Any and all guidance is appreciated and thanks for reading through.<\/span><\/p><p style=”text-align: center;”> <\/p><p style=”text-align: center;”> <\/p><\/p>\n","protected":false},"template":"","class_list":["post-396375","topic","type-topic","status-closed","hentry","topic-tag-fluent","topic-tag-heat-flow-1","topic-tag-radiation","topic-tag-solar-calculator-1","topic-tag-solar-loading-2","topic-tag-solar-ray-tracing-2"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t