3 research outputs found
Variation of Car Cabin Temperature Influenced by Ventilation under Direct Sun Exposure
Get PDFIn the past few years many fatalities have been reported as the result of internal car heat. Problems arise when the temperature in a car cabin is too hot when parked under direct sunlight. The trapped and accumulated heat causes the temperature inside a car to reach up to 36ºC and even up to 50ºC. The objectives of this paper are to study and analyze the behavior of car cabin temperature influenced by ventilation under direct sun exposure. The performance of the proposed mathematical modelling was compared to data collected in real time from the car cabin. The simulation model was used to study the behavior of cabin temperature by investigating the ventilation mass flow rate as its parameter. An experimental result was obtained from measurements on a salon car parked in the direct sun. It is hoped that this study will be able to provide beneficial information for car interior design and material selection in order to improve comfort levels in cars
Towards an airtightness compliance tool based on machine learning models for naturally ventilated dwellings
Get PDFPhysical models and probabilistic applications often guide the study and characterization of natural phenomena in engineering. Such is the case of the study of air change rates (ACHs) in buildings for their complex mechanisms and high variability. It is not uncommon for the referred applications to be costly and impractical in both time and computation, resulting in the use of simplified methodologies and setups. The incorporation of airtightness limits to quantify adequate ACHs in national transpositions of the Energy Performance Building Directive (EPBD) exemplifies the issue. This research presents a roadmap for developing an alternative instrument, a compliance tool built with a Machine Learning (ML) framework, that overcomes some simplification issues regarding policy implementation while fulfilling practitioners' needs and general societal use. It relies on dwellings' terrain, geometric and airtightness characteristics, and meteorological data. Results from previous work on a region with a mild heating season in southern Europe apply in training and testing the proposed tool. The tool outputs numerical information on the air change rates performance of the building envelope, and a label, accordingly. On the test set, the best regressor showed mean absolute errors (MAE) below 1.02% for all the response variables, while the best classifier presented an average accuracy of 97.32%. These results are promising for the generalization of this methodology, with potential for application at regional, national, and European Union levels. The developed tool could be a complementary asset to energy certification programmes of either public or private initiatives. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).This work was financially supported by: Base Funding - UIDB/04708/2020 and Programmatic Funding - UIDP/04708/2020 of the CONSTRUCT - Instituto de I & D em Estruturas e Construcoes - funded by national funds through the FCT/MCTES (PIDDAC). The author would like to acknowledge the support of FCT - Fundacao para a Ciencia e a Tecnologia, the funding of the Doctoral Grant PD/BD/135162/2017, through the Doctoral Programme EcoCoRe. This work is supported by the European Social Fund (ESF), through the North Portugal Regional Operational Programme (Norte 2020) [Funding Reference: NORTE-06-3559-FSE-000176]
Modelling and Force Tracking Control for Newly Type Configuration of Magneto-rheological Damper
Get PDFThe objective of this paper is to model hysteresis behaviour of new MR damper configuration by using nonparametric model approaches. The approaches are nonparametric linearised data-driven (NPLDD) single input model, non-parametric linearised data-driven (NPLDD) double input model, and simple polynomial model. The modelling is developed to ensure the force of MR damper is tracked to any input force. The NPLDD model is developed based on look-up table while the polynomial model is developed based on curve fitting from the experimental results and consists of a pair of subsystems namely positive and negative acceleration which corresponds to the upper and lower curves. From the simulation results, the NPLDD double input model shows better performance in describing non-linear hysteresis behaviour of the MR damper compared with others. By using the NPLDD model, a force tracking based on PI controller has been developed. It is verified that the NPLDD model together with the PI control strategy has the capability to track the desired damping force well
