2019 Austria

International KULI User Meeting 2019

| Linz, Austria

Tuesday, May 21st
09:00 KULI Newcomer Workshop | Engineering Center Steyr, St. Valentin, AUT
19:00 Welcome Dinner | Lentos Linz
Wednesday, May 22nd
08:30 Registration
09:15 Welcome and Opening C. Rathberger, Magna, AUT
09:30 Vehicle Thermal Simulation of a Super Sport Car F. Bastianini, Automobili Lamborghini, ITA

Challenges of coupling simulation and testing for top performance car, less weight and efficient design.

“New vehicle design and new powertrain require a major effort in terms of prediction capability of simulation tools, that can be reached only with some fundamentals steps. A robust model based on experimental data regarding the type of common performance targets of the vehicle, engine loads, component characterization, thermal management strategy; continuous modelling of the system with updates on components performance; layout optimization and test bench verification prior to build up the first running vehicle. This is the basis of thermal management optimization at Lamborghini for top performance car“ 

10:00 Thermal and Hydraulic Design of a Fuel Cell Car with KULI 12 and Co-Simulation Dr. T. Lichius, AUDI AG, GER

Due to the high complexity of fuel cell vehicles and its thermal management architecture a holistic development process, based on dynamic simulations is pursued. 

Therefore a Kuli based methology is shown to support the engineer in the early design phase of a thermal management system. Since all relevant sections of a development process e.g. longitudinal dynamics and power supply are also considered it is possible to get a first hint of the vehicles performace in early development phase.

10:30 Coffee Break
11:00 KULI Simulation Application in PHEV Vehicle Thermal Management Development S. Zhang, Magna, Shanghai, CHN

PHEV has a high complexity powertrain system, results in high demand of cooling system, meanwhile the air conditioning system is connected to the cooling system more closely. Both factors come together lead the thermal management in PHEV very challenging. What’s more, nowadays not only ensuring thermal safety is very important, but also a highly efficient and comfortable vehicle with optimized thermal control logic is the hot point as well. The focus of this presentation shows KULI as a professional VTM software, has indeed played a significant role on these topics during the PHEV thermal management system development.

11:30 Research and Application of KULI in BEV Heat Pump System Design Y. Zhao, Air International Thermal Systems,CHN

Heat pump system is more and more widely used in the battery electric vehicles (BEV) as heating solution instead of the high voltage PTC. Steady state heat pump system model is developed with good accuracy. 1D transient model coupled with 3D CFD result is developed to predict the heating performance and energy saving impact of heat pump system with dual layer HVAC. Through the comparison of Max heating and cabin average temperature between 2 Layer HVAC Heat pump system and PTC. The 2 Layer HVAC Heat pump system saved 1.8kwh elecyric energy. 

12:00 Moderated Discussions with Experts from our KULI VTM Team
  1. Future A/C and heat pump architectures and components
  2. Challenges in setting up coupled simulation environments
  3. System understanding for suppliers. What are the challenges and what can be gained?
13:00 Lunch Break
14:00 Simulating Heat Pumps in KULI – Modelling Approaches and Applications C. Rathberger, Magna, AUT

Heat pumps currently gain more and more importance in vehicle thermal management… especially in e-mobility applications. Regarding architecture, design and controls of such systems there are many different approaches… and many questions! This presentation highlights the most important heat pump types with their specific benefits and drawbacks and explains how they can be modelled in KULI. Finally, based on virtual application examples, we will show how VTM simulation can be used for investigating related energy saving potentials.

14:30 Stand-Alone Battery Thermal Management for Electric Two-Wheelers B. Mayer, Deutsches Zentrum für Luft- und Raumfahrt e.V., GER

Current electric vehicles are limited in their charging times with a C-rate of 2 to a minimum of 30 minutes from 0 to 80 % SOC. Charging times of 15 minutes are aspired by car manufacturers for future vehicles to shorten the waiting time for customers. Especially in electric two-wheelers fast charging is key to increase the attractiveness as range and thus battery capacities are limited due to volume and mass constraints. 

Both vehicle classes will be confronted with large waste heat losses during fast charging due to the joule heating of the battery cells. Mahle Behr estimates cooling capacities of 12 kW for battery thermal management for a 15 minute charge of an automobile with 100 kWh battery capacity. This would outperform the available cooling capacity of current HVAC systems, which can supply up to 8 kW during cabin cool-down. Keeping in mind that steady-state cabin cooling will require an additional power of 3 kW and that battery cell aging will double the battery heat losses, it is not possible to use current automotive battery thermal management systems for fast charging with more than 2C. Furthermore fast charging will be crucial to electric scooters and motorcycles as the available space and mass for batteries is limited. The cylindrical cells used in these vehicles show higher internal resistances than automotive cells which results in even bigger relative waste heat. 

This presentation presents an alternative approach and new solutions for battery thermal management for electric two-wheelers. By decoupling the battery thermal management from the HVAC the thermal management of electric vehicles can benefit from several advantages.

15:00 Thermal Management of Optimally Operated Hybrid Vehicles based on KULI Models within a Matlab Co-Simulation Framework M. Höfler, Magna, AUT

As consequence of the increasing hybridization and electrification in the automotive industry and the large variation of different concepts, the complexity of the powertrain is significantly increasing. Consequently there is a high interest to investigate the behavior of the different interacting components (E-Motor, ICE, battery…) already in simulation. Due to the fact that all powertrain subsystems are connected by the cooling system, especially this behavior and its influences on the whole powertrain has to be investigated in all details. Hence, within this work Kuli is used as thermal modelling environment which enables detailed modelling of each component. In order to consider all thermal effects for the proposed optimal hybrid strategy all information from Kuli is used in a Co-Simulation framework within Matlab and consequently the Kuli model information also influences the decisions of the applied optimal hybrid operation controller.

15:30 Coffee Break
16:00 Vehicle Level Thermal Performance Prediction Accuracy Enhancement by Modeling Non-Uniform Airflow Over Coolpack in 1D S. Jaybhay, Tata Motors, IND / C. Rathberger, Magna, AUT

Design, development and optimization of heat, ventilation and air-conditioning (HVAC) system and powertrain cooling (PTC) system is vital in the course of vehicle development or upgrade. Nowadays, the automotive OEMs are coming up with superior products with short development time. Quick, accurate and robust digital validation capability is crucial for rapid product development.

To evaluate the HVAC and PTC performance at vehicle concept stage, airflow over coolpack (condenser, intercooler and radiator) from benchmark or similar platform is considered. As the vehicle program matures, with availability of component level geometrical and functional data, airflow over coolpack is predicted in 3D CFD considering all underhood restrictions (grill, heat exchangers, engine block, etc.) and upstream components heat rejection. This eliminates the need of modeling the coefficient of pressure (Cp), built-in resistance (BiR) and coolpack fan in the 1D model for simulating airflow, as the combined effect of underhood restrictions and upstream heat rejection is already considered during the 3D CFD analysis. Hence, air mass flow rates over coolpack predicted by 3D CFD at various test conditions are directly used as an input in the 1D model. Additionally, hot air recirculation and correction factor for engine bench test data are also considered while simulating the 1D model. With consideration of all above phenomena, 1D CAE predicts the performance up to an accuracy of ~93% to 95%. In reality, airflow over coolpack is highly non-uniform, but it is considered as uniform in 1D analysis, which results into favorable PTC performance.

This work addresses the effect of non-uniform air flow over coolpack in 1D CAE by mapping the airflow velocities over the heat exchangers using velocity profile obtained from 3D CFD. The methodology developed in this work is validated against physical test data. Using the proposed methodology, HVAC and PTC performance prediction accuracy is enhanced up to ~95% to 97%. Further work will be carried out to generate a correction factor based on uniformity index in order to reduce simulation time and complexity of modeling.

16:30 Increasing energy efficiency and range of electric vehicles using radiator fan speed control S. Jaybhay, Tata Motors, IND / C. Rathberger, Magna, AUT

Electrical vehicle thermal management system is a critical element as it has to cater to cooling of various components based on their operating temperatures. Traction motor, battery pack, inverter, converter, vehicle cabin have different cooling requirements that have to be met for satisfactory performance of the vehicle. Any deviation outside the operating temperature range may cause de-rating of motor, malfunctioning of electronic components, drop in battery state of charge (SOC), etc. thus leading to reduction in vehicle range.

This work focuses on building a vehicle level one dimensional (1D) traction cooling system (TCS) model which simulates the cooling performance of the traction system components viz. traction motor, traction inverter and auxiliary inverter. A radiator and fan assembly is used to reject the heat absorbed by an ethylene glycol - water based coolant from the traction system components. The objective of this work was to develop a radiator fan speed based logic as a function of vehicle operating conditions, ambient conditions and traction motor inlet coolant temperature, to reduce the battery pack power consumption. The baseline performance prediction model was validated with steady state physical test data of limiting ambient temperature (LAT) for motor inlet. To build the above stated radiator fan speed based logic, the validated model was then used to predict the minimum fan operating speed required to meet the traction motor inlet coolant temperature target requirements for different ambient conditions and different vehicle operating conditions. Airflow over radiator for different fan speeds and ambient conditions was predicted by 3D CFD to get an input to 1D simulation.

1D TCS model was simulated for both continuous and peak load conditions on the vehicle to serve the complete operating range. Further work can be carried out to build the 1D transient model for predicting the instantaneous coolant temperatures.

17:00 End of the First User Meeting Day
18:30 Nostalgic Train | from Town Square Linz to Restaurant Pöstlingbergschlössl
19:00 Dinner | Restaurant Pöstlingbergschlössl
23:00 Nostalgic Train Back to Town Square Linz
Thursday, May 23rd
09:00 Heat Exchanger Development in Off-Road Vehicles B. Bauernfeind, Wacker Neuson Linz GmbH, AUT

How can we shorten and improve the actual vehicle development process with frontloading? This was also our first question before starting the simulation. Years ago we calculated new cooler by comparison of series production heat exchanger. We needed a lot of different coolers and fans to reach the limits of the engine and components supplier. 

The validation is costly and takes a lot of time in the production development process. Now with the frontloading process we can save a lot of time and money because we simulate every new excavators and dumpers. I provide you an insight how the cooler simulation process is working in our company with Kuli and with which obstacles we have to overcome now.

09:30 Benefit Studies for Using a Thermal Battery in an EV Application M. Keane, Sunamp Automotive, GBR

Thermal conditioning of electric vehicles can have a severe impact on the available driving range. Especially in winter conditions heating the vehicle via a PTC heater consumes a lot of electric energy. Sunamp has developed a portfolio of thermal batteries (latent heat storage devices) which take a different approach to this topic. Especially the  capability of using waste heat for charging the thermal batteries is very beneficial for overall vehicle efficiency. In this presentation we will use KULI simulation models to demonstrate potential positive effects of thermal batteries on the annual energy consumption of an electric vehicle. We will also show some key applications from the Sunamp product portfolio.

10:00 Use of KULI for Electric Vehicles M. Bergmans, Altran Engineering B.V., NLD

One of the main focuses of Altran Engineering is the development of electric vehicles. The cooling of electric vehicles is different compared to conventional vehicles with a combustion engine. In a conventional vehicle, there is only one major heat source which generates a large amount of heat. In electric vehicles, there are multiple components which generate small amounts off heat. Besides that, the requirements on flow, pressure and temperature are different for electrical components. Altran Engineering uses KULI to simulate the performance of their electric vehicle’s cooling systems, select the right cooling pumps and perform further investigation on how to improve the cooling systems.

10:30 Coffee Break
11:00 Validation of Radiator Performance during Highly Dynamic RDE Operating conditions A. Traussnig, AVL List, AUT

Due to increasing demands in terms of energy efficiency, vehicle thermal management has gained importance. That is the reason why many new engine generations have a mechatronic Thermal Management Module to control the distribution of the energy flow. This mechatronic module allows a fully controllable and fast variation of the coolant flow and temperature over the full engine operating range. It operates almost lag-free – switching from zero to full flow takes usually less than one second. The introduction of these new mechatronic modules leads to a different coolant flow and temperature dynamics and therefore new requirements in the field of thermal simulation and conditioning at the testbed arise. In extreme driving situations a maximal temperature gradient of 60 K/s at the engine inlet respectively radiator outlet can be observed. For the CO2 emission evaluation during RDE drive cycles this dynamics need to be reproduced; first by simulation then by the conditioning unit at the test bed. In terms of transient coolant conditioning a conditioning unit names “Dynamic Module II” was developed. To control the conditioning unit and to emulate real world transient temperature traces on the testbed a heat exchanger model that is capable of predicting the timely evolution of the engine coolant inlet temperature - in real time – is required. Thus the contribution of this paper is to evaluate the dynamic behavior and computation time of the KULI 13 radiator model and the dynamic solver by comparing it to step response measurements. To provide the required test results a transient radiator test rig was designed which allows to rapidly switch on/off the air and the fluid flow through the radiator.

11:30 Developing the Electric Drivetrain of Tomorrow – How Numerical Tools can Support the Design Process and Improve System Understanding P. Laaber, Magna, AUT

We are right at the beginning of the new mobility era with deep impact on the architecture of cars. Hybridization and electrification are the dominating topics in the automobile industry and consequently the powertrain of cars gets into the focus.

However, the development of smart and efficient drive assemblies is challenging due to different and increasing demands such as legal restrictions. Numerical simulations can provide profitable support in the development of such components, especially when they are adopted during the early stages of the design process.

The focus of the presentation consequently lies on the virtual part of the development process and the employed numerical tools. Different levels of modelling from detailed 3D models on a component level to 1D simulation on a system level and how they can be connected are covered. First the design of a passive lubrication concept in gearbox is shown. The complex multiphase flow represents the challenge for numerical simulation in this case. The gearbox model is then combined with the electric motor and the invertor to a thermal 3D model of the entire electric drive unit. A 1D thermal network of the electric drive unit can be subsequently derived. This thermal network model is finally integrated in the cooling system model of the car, which then allows to study the thermal situation of the entire cooling system as well as powertrain components under transient conditions.

12:00 The Role of Thermal Management in High Fidelity Modeling of Electric Drivetrains C. Stroh, Magna, AUT

Within the EU project “HiFi Elements” a methodology is developed for the simulation, optimization and verification of e-drivetrains with the help of standardized interfaces and co-simulation, allowing easy exchange of individual components, including different complexity levels of the individual components. The thermal model is considered as a “component” in this context. This lecture describes the role of the thermal model in this framework, how it is set up in KULI and how it interacts with the other models in this environment.

12:30 Changing the Landscape of Corporate Innovation A. Schilling, JFDI, AUT
13:00 Lunch Break
14:00 KULI 13 | New Features and Road Map M. Kovac, Magna, AUT
14:30 KULI Tips & Tricks Live | Some Modelling Highlights Presented and Explained KULI Team
15:30 Coffee Break
16:00 KULI Tips & Tricks Live | Some Modelling Highlights Presented and Explained KULI Team
17:00 Official End of the KULI User Meeting