Cooling performance simulations in GT-Suite

Abstract: This project was performed at Volvo Trucks in Gothenburg, Sweden. It was done incooperation between Volvo 3P and Volvo Powertrain.There are different methods for doing cooling performance simulations. Thesesimulations can be done in 3D by using Computational Fluid Dynamics software orby using 1D simulation tools. The main task for this project was to evaluate one of the1D simulation tools.The Cooling analysis group at Volvo 3P uses AMESim and KULI as 1D simulationtools in its work. It was decided to try GT-Suite for such simulations. One of thereasons for this decision was that Volvo Powertrain is using this program for enginesimulations. When using one tool for both simulations there is a possibility to couplethem together and obtain a more precise simulation model with high level ofintegration.As a first step for the project a model of the cooling system of a Volvo FH truck wascreated and the simulation model results were evaluated against the experimentalresults. Further on a module of GT-Suite for detailed modelling of the underhood flowin 3D environment called Cool3D was used to construct a model of the coolingpackage and its surroundings. This model was added to the initial model and theresults of the simulation were compared to the first simulation and experiment.The first model constructed was using a mapped engine for obtaining heat releasevalues of different components, meaning that heat release was only dependant on theengine load and speed. To improve this model a mean value engine model wasobtained from Volvo Powertrain and the two models were coupled one to another.As a result of the project it was shown that a simple 1D simulation requires tuning asit is impossible to include all the details for the air side of the cooling system, but afterthe tuning been done it can definitely be used.It was shown that tuning could be omitted when using Cool3D tool and taking intoaccount the effect of hot air recirculation via ambient air preheating.For the coupling of cooling system and engine simulations it was shown that it ispossible and can easily be done, a brief description of how to do it was given.