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Pretty hard to determine optimal fin spacing, fan profile and heatsink material/dimensions through trial and error. Honestly your best bet would probably be to test an array of existing heatsinks and fans to find an optimal spacing and size of fin and then try your best to copy that.The reality is that in order to properly model and optimize a heatsink, you're going to need some pretty hefty tools. You need to be able to accurately model/account for air turbulence (or lack thereof), rate of airflow, laminar flow and boundary layer adhesion among other things. Furthermore you'll need to be able to accurately model thermal transfer from your IHS to the various areas of your heatsink as it is very much not uniform. On top of this, you also need to be able to accurately assess the airflow profile of your fan of choice and optimize that as well. I am presently doing exactly this and according to the thermal design engineer I am working with the COMSOL license we're using is around 5000USD for a student license and closer to 10-15K for a commercial single user license.Again I don't think it is that simple. Look up boundary layer so you can understand how the surfaces of the cooler will reduce airflow as it passes. Fin spacing basically comes down to having the minimal distance at which adequate air can move between the fins for optimal transfer. Too close and airflow will slow/alter on its way through killing cooling. Too far apart and you're going to get good cooling, but you're wasting surface area.
Pretty hard to determine optimal fin spacing, fan profile and heatsink material/dimensions through trial and error. Honestly your best bet would probably be to test an array of existing heatsinks and fans to find an optimal spacing and size of fin and then try your best to copy that.
The reality is that in order to properly model and optimize a heatsink, you're going to need some pretty hefty tools. You need to be able to accurately model/account for air turbulence (or lack thereof), rate of airflow, laminar flow and boundary layer adhesion among other things. Furthermore you'll need to be able to accurately model thermal transfer from your IHS to the various areas of your heatsink as it is very much not uniform. On top of this, you also need to be able to accurately assess the airflow profile of your fan of choice and optimize that as well. I am presently doing exactly this and according to the thermal design engineer I am working with the COMSOL license we're using is around 5000USD for a student license and closer to 10-15K for a commercial single user license.
Again I don't think it is that simple. Look up boundary layer so you can understand how the surfaces of the cooler will reduce airflow as it passes. Fin spacing basically comes down to having the minimal distance at which adequate air can move between the fins for optimal transfer. Too close and airflow will slow/alter on its way through killing cooling. Too far apart and you're going to get good cooling, but you're wasting surface area.
