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The automotive market is very competitive and demands consistently improving the technologies used and reducing the product cost and dimensions with each product model iteration. Hence, it is important to have access to well-defined reference designs of high-quality products to evaluate new ideas and technologies. This paper provides readers with a numerical model of such a high-quality product, i.e., the IPMSM-type traction motor from the fourth generation of the Toyota Prius hybrid transaxle. The presented results also serve for a discussion regarding the design decisions of the Toyota engineers and the applicability of the linearized machine model for the approximated torque calculations. In the introductory section, a brief history of the Prius model and references to the reverse engineering reports are given. Afterward, the machine dimensions, material properties, and winding configuration are described. Then, the model is validated with the torque measurements at constant speed. The simulation results are presented in the next chapters, and the numerical source data are supplied to the reader. Finally, the design philosophy of the Toyota drive is briefly discussed in comparison with the BMWi3 drive and the results are concluded in the last section.

Air pollution is a significant problem in city centers. According to public health care in Poland, there is a need for local authorities to propose good purification solutions in both outdoor and indoor conditions. The main objective of this study is the development of an appropriate filtration system for public transport, especially for buses and bus stops. Firstly, the authors justify the need for air filtration in the capital of Poland, Warsaw. The average concentration level of PM10 and PM2.5 dust particles in large Polish cities is presented. In addition, it is underlined that PM2.5 dust particles are carriers for coronavirus COVID-19 and easily inhaled by humans. In the next step, the authors introduce an experimental stand used in the examination of different filtration baffles. The filtration efficiency is defined and calculated according to experimental examinations. In these experiments, an antismog cover for air-conditioning split systems, an H13 HEPA filter and a three-stage filtration baffle (active carbon + F5 filter + EPA11 filter) were taken into consideration, and the efficiency of filtration under pressure-drop conditions and the influence of moisture were ascertained. The best filter setup was thereby determined to be the three-stage filtration baffle, being the most efficient in cleaning air on account of having the smallest mass concentration of PM2.5. This indicates that three-stage filtration is the most suitable air-filtration method for public transportation in cities where air pollution is a serious concern.

In the proposed paper, non-equilibrium and equilibrium models of heat and moisture transfer through wet building materials are presented and compared. In the former, the mass transfer between liquid and gaseous moisture results from the difference between the partial pressure of water vapor and its saturation value. In the second model, the equilibrium between both phases is assumed. In the non-equilibrium model, liquid moisture can be in the continuous (funicular) or discontinuous (pendular) form. The transfer of moisture for each proposed model is tightly coupled with the energy transfer, which is assumed to be an equilibrium process. The time step and grid size sensitivity analysis of both numerical models are performed primarily. The verification of the model is based also on the numerical data available in literature. Finally, obtained with considered models, temporal variations of moisture content in three locations in the computational domain are compared. Reasonable conformity of results is reported, and discrepancies related to differences in formulations of models are discussed.