CAD Simulations: Cooking a Turkey

While I was deciding on an appropriate brine, rub and injection for this years Turkey I was curious how closely a quick and dirty simulation would come to the reality of my smoker out on the deck? So while I was waiting for the bird to thaw I started modeling one up.  Then, to calculate the fowl temperature versus time I used a 4 step process:

1. Gather Data and make Assumptions:

– I’m assuming homogeneous thermal properties.

– Assuming the majority of heat transfer is via convection not accounting for radiation.

– I’m modeling the turkey while cooking dinner so bones are not added. If anyone has a full 3D Turkey skeleton send it on over.

I found some thermal properties for meats here:

http://www.engineeringtoolbox.com/specific-heat-capacity-food-d_295.html

– Most of the standard material properties in Flow are temperature dependant however for this study I’m assuming conductivity and specific heat are basically constant in this temperature range.

– Assuming constant ambient temperature.  When I get a second probe with recording capabilities I will try again with ambient temp(time).  Ideally with the control system on the pellet smoker it’s pretty consistent so it’s not too big of an assumption.

Step 2. Create a Steady State Flow Simulation of the Smoker:

With Flow I used parametric studies to estimate inlet flow rate and temperature to create a steady state ambient temperature of 325F.  I will use the ambient temperature and convection heat transfer coefficients from Flow rather than estimating them as boundary conditions in thermal.

Cut Plot of Ambient Temperature in Flow

Heat Transfer Coefficient on Surface Note it is NOT uniform

Step 3.  Run transient thermal simulation:

The transient study was run in thermal analysis to reduce tun times.  Running the full smoker model in Flow as a transient would take much longer to run. However we did use Flow to capture the non uniform convection which would be more difficult to apply in thermal.

Transient Thermal Simulation Using Flow Convection

Now you not may be able to tell from the picture but I was in the holiday “spirit” and forgot to save my temperature probe data from the Turkey…..

author trying not to cut off a finger

Calibrating my model

Smoking

Finshed!

Step 4:  Conclusion/Comparison:  Time versus temperature calculations 

Analysis Compared to Thermal Probe Temperatures over Time