The laboratory or its team deals with the research and development in the field of air-conditioning systems that are employed to adjust indoor environment quality of vehicle cabins or buildings; it also includes testing the system effect on thermal comfort. The main demand today is development and design of such air-conditioning systems that provide optimum thermal comfort at the lowest energy and operating costs.

In order to create high quality and comfort environment inside a vehicle cabin, it is, first of all, necessary to provide cooling/heating and sufficient ventilation rate. Engineering systems that provide this functionality are acronymically called HVAC systems which comes from heating, ventilation and air-conditioning systems. Features of such systems and their impact on the quality of ventilation, air-conditioning and thermal comfort are typically tested by means of either simulations or measurement involving real models. For simulations of systems and indoor environment of buildings and cabins, the department employs CFD and 1D simulation tools. The tests conducted on real models are carried out at the department facilities equipped to measure parameters of indoor environment with the use of a thermal manikin, a small size airplane cabin mock-up and a climate chamber for functional testing of systems under conditions that correspond to real operation.

Activities carried out

• Simulations of vehicle cabin environment
• Thermal comfort assessment
• Calculation and simulation of cabin thermal balance
• Models of human thermal comfort
• Assessment of thermophysical properties of clothing
• Ventilation quality assessment
• Air duct optimisation
• Simulations of building indoor environment

Laboratory instruments

• Newton thermal manikin
• Portable system for measurement in car environment
• Small airliner cabin mockup
• Climate chamber

Software models developed

• Cabin heat load model - The model aims at prediction of heat load and parameters of car cabin indoor environment under real operating conditions. Its current version is derived from a particular car make by employing its geometry and material composition. Based on boundary conditions: ventilation parameters (flow rate, temperature and relative humidity of the supplied air), driving parameters ( speed, car orientation to sun) and number of people in the car, environmental parameters in the car such as air temperature and relative humidity can be predicted. At the same time, it is possible for the cabin heat load to be calculated hence the need for heating/cooling. The previous model was created within Dymola environment (Modelica language), the newer one relies on Matlab.

• Thermal comfort model of a human being - The model is intended for predictions of thermal comfort in inhomogenous environments (e.g. vehicle cabin). Based on parameters of the surroundings (temperature, mean radiant temperature, relative humidity, air speed) and a human being (clothing, activity), it predicts surface temperature and respective thermal sensation. The model is derived from Tanabe’s physiological model of human being and Zhang’s thermal comfort model. It was created within Dymola environment (Modelica language).

References

• Selected problems of environmental engineering (2017-2019). Identification code: FSI-S-17-4444.
• Innovative control of a car cabin HVAC system as a part of an Advanced Driver Assistance System (2014-2017). Identification code: TA04031094, The project will focus on improving the safety of vehicles and reduce accidents. The aim of the project is to develop a system that would help avoiding dangerous situations in which the driver gets in particular because of thermal discomfort in the cabin (i.e., high or low temperature for each segment of the body surface) and consequently often difficult manipulation with the controls of the heating / cooling system such as directional manipulation of ventilation outlets, switching positions and fan performance.
• Josef Bozek Competence Centre for Automotive Industry (2012-2017). Identification code: TE01020020,Involvment: WP 22 - Human Centered Cabin Design
• Complex modelling of the interaction between human being and the environment of a vehicle cabin or residential spaces, and respective design tools (2011-2013). Identification code: FSI-S-11-6, Participation in design tools and air distribution systems development.
• iSPACE - inovative Sytems for Personalised Aircratf Cabin Environment (2010-2012). Methodology development for selection of suitable technology concepts of individualised microclimate – project task WT 2.3 - Selection of Concepts for Individualised Cabin Environment. CFD model of personalised ventilation outlets and a case study of their effect/performance on thermal comfort – project task WT 2.2 - Simulation and Parameter Study. Detailed CFD model of the entire cabin including all technology tested, evaluation of simulations, thermal comfort and results validation against measurement – project
• Airspace research centre - CLKV (2005-2011). Within the frame of research task A6 – Prediction of indoor environment in aircraft cabins, the issue of predictions indoor environment in a small aircraft cabin was solved with the use of CFD simulations and 1D simulation programmes. The assessment methodology of thermal comfort that employed comfort zone charts along with a virtual passive manikin  was completely implemented. Close attention was paid to effects of the air duct geometry and air distribution strategy on the passengers thermal comfort and ventilation quality.
• Junior project – Development of a 1D model of a car cabin for indoor environment parameters prediction (2011). The project focused on pilot development of a 1D car cabin model for prediction of indoor environment parameters as well as data acquisition for validation of simulation results. The data were obtained during real car road tests (traffic type: city, countryside, motorway).

cooperation

• Škoda auto a.s.
• EKC/3 - Heating and air-conditioning system development
• V. Klementa 869 | 293 60 Mladá Boleslav | Czech Republic
• Kontaktní osoba: Bc. Jan Hrnčíř, Ing. Michal Závodník
• 
• Volkswagen Corporate Research
• Vehicle Technology
• CAE-Methods
• D-38436 Wolfsburg|  Germany
• Kontaktní osoba: Dr. Viktor Bader   
   
• MAN Truck & Bus AG
• Engineering Karosserie Bus Components (EKBC)
• Entwicklungsingenieur Heizung, Lüftung, Klima / HVAC
• Dachauer Straße 667
• D-80995 München
• Kontaktní osoba: Frank Seidel   
• 
• Indoor Environment Department
• Group Indoor Climate Systems
• Fraunhofer Institute for Building Physics IBP
• Holzkirchen Branch
• Fraunhoferstraße 10 | D-83626 Valley | Germany
• Kontaktní osoba: Dipl.-Ing. Gunnar Grün

Contact person

Ing. Jan Fišer, Ph.D.
Energy Institute, FME BUT
e-mail: fiser@fme.vutbr.cz
tel.: +420 541 143 242