Review 2021 - KULI

• Different architectures for electrification in the industry
• YMERs standardized and modular Thermal Management Solution​​​​​​​

Due to the requirements of the Euro 6 standard, a new engine with a new developed exhaust gas system had to be implemented in a military vehicle. Since higher temperatures had to be considered also in the cooling rig behind the cabin simulations were performed to give a preview of expected temperatures, help to dimension the cooling package, give an assumption for preferred position of components in the rig and master the challenge of integrating the engine.

The presentation will give insight in a use case of a simulation workflow which combines the advantages of 3D CFD Simulation and 1D KULI Simulation. The results of several loops will show how the workflow lead the engineers to a well performing cooling system and an optimized cooling rig packaging for the military vehicle.  For the validation of the combined workflow the presentation will show measurement results from the dyno test in comparison to the simulation results.

Mobile Air Conditioning (MAC) system is critical sub-system as it provides thermal comfort to the occupants. In present scenario, 1D CAE simulation tools are widely used for MAC system design, component sizing/ selection and AC cooldown performance prediction. Component sizing and selection mainly depends on heat load which varies with cabin geometry and its thermo-physical properties, hence detailed modeling of car cabin is essential for MAC system digital validation.
There are two different methods available in KULI for car cabin modelling, viz. simple cabin and advance cabin model. With the simple cabin modelling, car cabin is modelled as a group of lumped masses, which only enables prediction of average vent and average cabin temperatures. In advance cabin modelling, car cabin is modelled comprehensively. The inputs parameters for advance cabin model are vehicle geometry, thermo-physical properties of cabin material, conditioned air mass flow and diffusion field generated in 3D CFD. Advance cabin model enables prediction of cabin air temperature distribution inside a car which is closer to the real world scenario.
This work discusses the approach followed to model advance cabin in 1D CAE for two row car cabin. After incorporation of detailed cabin inputs, conditioned air mass flow and diffusion field, series of iterations were conducted to correlate the transient AC vents and occupants nose level air temperatures with physical test results. Accuracy of 95% for occupant’s nose level temperature prediction was achieved for severe ambient condition. Along with conditioned air temperature distribution, refrigerant suction and discharge pressures were well correlated with physical test results. Further the impact of cabin insulation thickness and glass inclination angle on cabin air temperature distribution is also analyzed.

Open forum to ask our experts questions about current KULI and technology topics. Feel free to send your questions to KULI Support​​​​​​​ in advance or ask them directly during the session.

We want to give a short overview about how KULI can be used to investigate the potential benefits of supplier components and modules in complete vehicle use-cases. Such investigations allow OEMs to better understand the advantages generated by new and innovative technologies… especially regarding typical vehicle key performance indicators like effective range or cabin comfort parameters. Accordingly such simulations can provide valuable sales arguments for supplier companies.

One relatively easy way to demonstrate the benefit of a VTM component is virtual installation into existing, validated vehicle simulation models and do before/after comparisons. At Magna we have several such vehicle models available… in the section following this introduction we will highlight some work we did with three different partner-companies over the last two years. All of these studies were based on the Magna E1 demonstrator car / Tesla S, which we will briefly introduce here.

• Cold battery cells reduce vehicle efficiency, performance and charging capacity, while extreme heat reduces the lifespan
• Even relatively thin layers of suitable insulation material can limit battery cool-down in winter
• Simulation of over-night cool-down and subsequent drive cycles shows significant range benefit potentials
• Simulation of day-time heating under sun shows effect on battery cell life

Cabin insulation is a key factor for HVAC system performance and efficiency in electric vehicles.​​​​​​​ Both on hot summer and cold winter days, the HVAC system of an electric vehicle faces significant challenges:

• As the peak power of an electric compressor is limited, fast cool-down of a hot-soaked cabin under high solar loads can push the AC system to its limits
• The high-energy consumption in these high-load operating points has a strong impact on the vehicle range
• In winter, the effort for cabin heating can become even higher, both due to fresh air requirements and high-temperature gradients between warm cabin interior and cold ambience

 In a joint project, Magna ECS and Honeywell have investigated the impact of cabin insulation under these conditions. Based on an existing baseline-vehicle simulation model, we added an insulation layer inside all cabin walls (except windows). We then compared the WLTC [spell out] vehicle range prediction for cases with and without added insulation. We also compared cabin cool-down and warm-up times. The results show that cabin insulation can contribute significantly to more efficient electric vehicles.

The limited range is one of the most crucial constraints of electric vehicles. Especially in winter, increased heating for pleasant temperatures and extensive use of air conditioning for dehumidification have an impairing effect on the vehicle range. Our approach targets the humidity in the cabin; a coating on the windshields prevents the formation of droplets, resulting in higher air recirculation rates and reducing the energy consumption of the heating system.​​​​​​​

Our clear transparent coating has a highly hydrophilic surface which avoids droplet formation by spreading of water. Applied on the whole windscreen, the drivers sight stays clear even with a high cabin humidity. This enables significantly higher air recirculation rates, which significantly reduces the energy consumption of the heating system. The company Magna applied this technology in a complete vehicle simulation model and subsequently derived the resulting potential for range improvement in e-vehicles. Furthermore, the coating is characterized according to the ECE R43. Optimization pathways to fulfil these requirements are currently under investigation.

Open forum to ask our experts questions about current KULI and technology topics. Feel free to send your questions to KULI Support​​​​​​​ in advance or ask them directly during the session.

​​​​​​​This presentation will talk about use of KULI with an optimization workflow for reducing time in the process of Front End module design during an RFQ Phase. This proof of concept use an MDO (Multi-Disciplinary Optimization) methodology combined to KULI model and surrogate model for quick optimal decision making on the best Front End Module. First, introduction on the limitation of current methodology for Front End Module optimization will be done. After, MDO methodology will be briefly explained before to illustrate one application and conclude about potential on this new methodology. For this automation process KULI, Excel VBA and Python code were used

In this era of a sustainable energy revolution E-vehicle has come up as one of the most emerging fields, whose mileage however is severely shortened by the positive temperature coefficient heater (PTC) in cold working conditions. To alleviate this problem, a thermal management system with waste heat recovery is investigated in this paper with both experimental and theoretical methods...

A KULI model was created to simulate an organic Rankine cycle (ORC) system for the test of thermal performance of boilers and condensers used in ORC systems for heavy duty off-highway vehicles. The system was controlled to achieve the requested test conditions through KULI’s optimisation process. It was found that possibly due to the dis-continuity of input data to KULI phase change heat exchanger components, KULI optimisation results depend on the pre-set parameter bounds and sometimes fails to find the optimal solutions.
A simple KULI system including only non-phase change heat exchangers was optimised by using KULI’s optimisation method and MATLAB’s optimisation algorithm to validate MATLAB scripts developed for its coupling with KULI. A good agreement was achieved between the optimal results of the two methods.
A case study using KULI and MATLAB coupled with KULI was then carried out for the ORC system in which 6 system operating parameters were optimised to achieve 6 system control targets. Sensitivity analysis to design parameters’ variation bound showed that MATLAB coupled with KULI is more robust and flexible but with much longer simulation time compared with KULI.

The eMobility market faces a lot of challenges such as high cost pressure due to changed regulations and consumer requirements. To support the OEM with strategical and conceptual decisions in this high complex environment it is crucial to understand the complete system and solve the target conflicts with respect to technical and commercial dimensions such as efficiency, performance and cost.

Therefore, Magna Powertrain developed an overall generic electrified powertrain cost model.

Based on an improved reference design and results of various simulations within different software, e.g. KULI for Thermal Management, all components, modules, technical data and commercial data have been combined and integrated in the model. Consequently, the established tool allows an allover system understanding regarding costs already in an early phase of the product development process. ​​​​​​​

We want to share our experience of the positive benefit of working closely with the KULI team to support our prospective customer simulated integration of thermal storage in electric car heat pump thermal system. This work showed that integrating a high temperature thermal store gave faster warm up phase, improved system energy efficiency and eliminated certain components that reduced overall system costs.

Open forum to ask our experts questions about current KULI and technology topics. Feel free to send your questions to KULI Support​​​​​​​ in advance or ask them directly during the session.

Will hydrogen be the fuel of the future? If yes, for passenger cars? For trucks? For trains? For off-highway vehicles? Will hydrogen be needed as an energy carrier to avoid CO2 emissions? Dr. - Ing. David Wenger is one of the most experienced experts for hydrogen technology in the world. His company has done more than 600 projects on six continents in hydrogen, electric mobility and energy efficency. His presentation will give an overview on the state of the art in hydrogen technology and ist applications in mobility.

We will give an overview of the most important thermal management related properties of fuel cells and how to describe them in a formal way. Then we will show how to implement this in KULI and integrate the fuel cell model in a complete vehicle. This will include both impacts on the VTM system architecture and consideration of the required control strategies.

For alternative powered vehicles, such as fuel cell electric vehicles, the overall vehicle efficiency has to be forced to a maximum without reducing the passenger comfort. The interaction between powertrain and HVAC increases, which is handled with thermal management. To realize faster development and time to market cycles, the thermal management of new technologies are investigated virtual with simulation. As conditioning the cabin is one of the main energy consumers this presentation will elaborate an innovative conditioning concept to support or even substitute the vehicles conventional air-conditioning by simulation of an overall vehicle model.
The cooling system is based on the reversible reaction of metal hydrides with hydrogen and uses the pressure difference between a high-pressure hydrogen tank and the fuel cell system to provide heat and cold without producing water. So, without changing the chemical state of the hydrogen. Based on an existing lab-scale prototype, the mathematical model of the processes was validated and been implemented into the simulation platform “KULI”.
This contribution discusses the integration strategy of such a metal hydride air conditioning system into a fuel cell car and elaborates its impact on energy consumption and corresponding driving range in numerical simulations. Integrating a coolant to air heat exchanger into the HVAC box allows using both cold coolant from desorption side of the MeH reactor in summer and hot coolant from the absorption side in winter. Our results demonstrate significant energy saving potentials by reducing the utilization of electric climate compressor and electric PTC heater. Simulations also show that these benefits are not achieved by reducing passenger comfort, but instead both cool-down and warm-up times are even reduced.

Open forum to ask our experts questions about current KULI and technology topics. Feel free to send your questions to KULI Support​​​​​​​ in advance or ask them directly during the session.