Corrosion in the field manifests over a large timescale so when considering material choices in the design of aerospace systems and subsystems use is often made of accelerated tests such as ASTM B117 salt spray chamber test to rank the possible materials. Even these ‘accelerated’ tests take more than 1000 hours and despite their widespread use are often criticized as a design trade tool since the test environments are considerably different to the expected field environment running the risk of either hiding true corrosion processes or simply being unrealistically challenging for the materials under test.The corrosion community has expended substantial effort in trying to make the tests ‘more realistic’ but in doing so there is considerable debate about whether the tools employed to accelerate the corrosion (thermal cycling high salt concentrations UV exposure etc) actually introduce other corrosion processes that are not even present in the eventual targeted field of operation for the device under test.Computational techniques hold a great deal of promise as a way to understand the effects of different service environments but if the simulations cannot even discern between say an ASTM B117 test and an atmospheric exposure then the simulation results would be of questionable value.The processes involved in corrosion are many and complex however one key parameter is the electrolyte film thickness which will clearly be different whether inside a chamber at high humidity with a continuous supply of sprayed saltwater compared to exposure on a beach where diurnal cycles result in a very thin electrolyte of varying salt concentrations except of course when it is raining!To help designers quickly assess corrosion risk and choose appropriate materials Corrdesa have already developed an electrochemical database of modern alloys and coatings. This has been extended by deconvoluting the polarization data to accurately account for the impact of the actual electrolyte thickness on the oxygen reduction reaction.In this paper using fluid shell elements in a free surface flow formulation we actually predict the variable electrolyte film thickness in a CFD (Computational Fluid Dynamics) code for a given environmental condition on different test specimens and geometries. The appropriate polarization data for the local electrolyte thickness is then implemented with User Functions in a potential model framework. In this way the galvanic corrosion is simulated for a test device with a more realistic and variable film thickness.The result is that we can dial different test conditions into the simulation such as whether we wish to simulate chamber results or field results cyclic salt fog cyclic humidity (or both).Keywords: Computational Corrosion Analysis Galvanic corrosion prediction FEA corrosion prediction polarization data potential model fluid shell elements CFD