A physically based approach to model vehicle dynamics, transient engine performance and engine thermal management system is presented. This approach enables modeling dynamic processes in the individual components and is the dynamic interaction of all relevant domains. The modeling framework is based on a common innovative solver, where all processes are solved using tailored numerical techniques suited to account for characteristic time scales of individual domains. This approach enables achieving very short computational times of the overall model. The paper focuses on the integration of cooling and lubrication models into the framework of a vehicle dynamics simulation including transient engine performance demonstrated on a modern passenger car featuring split cooling functionality. A validated model with a mechanically driven coolant pump provides the base for analyzing the impact of introducing an electrically driven coolant pump. Analyses are performed for two drive cycles featuring significantly different velocity profiles to reveal their influences on the operational principles of the powertrain components and their interaction. The results show for both drive cycles fuel saving due to the application of the electric water pump is relatively small and amounts between 0.75% and 1.1%. However, it is important to address that application of the electric coolant pump results in higher turbine outlet temperatures and thus in faster catalyst heat-up. Detailed analyses of the interaction between vehicle dynamics, transient engine performance and engine thermal management system provide insight into the underlying mechanisms. This is made possible by the application of physically based system level model. brake mean effective pressure crank-angle combustion combustion products central processing unit differential algebraic equation engine control unit exhaust gas recirculation engine thermal management electrical water pump fuel burned friction mean effective pressure fuel vapor heat transfer liquid heat exchanger conductive heat transfer element convective gas heat transfer element convective liquid heat transfer element internal combustion engine Japanese test cycle lumped mass mechanical water pump new European drive cycle ordinary differential equation rate of heat release spark ignition turbocharged gasoline direct injection three way catalyst element acceleration vector (m/s2) area (m2) capacity matrix (variable) momentum to mass connection matrix (–) constrain matrix for accelerations (–) heat capacity (J/kgK) constrain matrix for momentums (–) diameter (m) flux vector (variable) generic right-hand-side function (–) gravity acceleration (m/s2) specific enthalpy (J/kg) enthalpy flow (W) loss coefficient (–) length (m) mass (kg) mass flow (kg/s) mass matrix (kgm2) element torque (Nm) speed (rpm) perimeter (m) pressure (Pa) specific gas constant (J/kgK) system matrix (variable) time (s) temperature (K) specific internal energy (J/kg) volume (m3) velocity (m/s) mass fraction (kg/kg) species flow vector (kg/s) state vector (variable) spatial coordinate (m) efficiency (–) thermal conductivity (W/mK) friction coefficient (–) density (kg/m3) torque (Nm) state vector (variable) integration increment, time, crank angle (–) angular position (rad) channel shape factor (–) angular velocity (rad/s) active species all additional blow by combustion cross section component cylinder downstream element heat transfer hydraulic element index inlet injection element index element index losses outlet passive species piston ring pump upstream wall ∗The “bold B” represents two different matrices. 
Assessment of engine thermal management through advanced system engineering modeling