Dear Santa!

In one night around the world must be very exhausting for you and your reindeers. But don´t worry Simcenter STAR-CCM+ can be at your fingertips to make life easier! I took the liberty to investigate your reindeer’s assembly configuration for optimal drafting. However, unlike drafting for bicycle groups, I also wanted to help your reindeers to fly at ease by maximizing their lift force at the same time.

1 mainImg


Optimization setup

So, I started of from a classic harnessed team of 6 of your reindeers and vary 12 coordinate parameters. Each reindeer gets an individual XY-position in front of your sleigh. Additionally, for your comfort, I restricted the maximal resistance acting on you such that you can ride in the slipstream of Rudolph and his friends.

Using the Design Manager in STAR-CCM+ allows me to access the parameters defined in the simulation. Leveraging the pipelined process in STAR-CCM+ for geometry and mesh operations transforms then automatically each reindeer to its designated position.

1 santaOpt XY Plot



400 alternative assemblies were tested virtually to find that the lift of the reindeers only increases with larger space between them and free inflow. This, however, increases the overall drag compared to the baseline configuration, where reindeers inside the slipstream experience less drag.

1 Kraniche Okt 2015


Well, the final configuration looks somewhat alike birds v-shape formation. However, the reason here is not the up wash which originates from the wing-tip vortices and that birds utilize. In this case, lift could easily be increased during the optimization because of the shape of the reindeer’s neck. This directs a portion of the flow upwards and thereby lifts the reindeers.

Santa, if you like to know more about the optimization in Simcenter STAR-CCM+ please feel free and drop me a note


We at Volupe wish you happy holidays!



CAD models courtesy of GrabCAD community. Reindeer: Dima Brahim Sleigh: Abm

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