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Optimization of the electric bus radiator design in terms of noise emissions and energy consumption by computational fluid dynamics

Janicka Anna, Zawiślak Maciej, Głogoza Artur, Włostowski Radoslaw

Combustion Engines

2022

R. 61, nr 4

41--50

The paper presents the numerical optimization of an innovative radiator for use in electric buses in terms of energy consumption and noise emission. Computational fluid dynamics simulations were performed. The flow of the cooling medium was modeled using the RANS method. The two-equation k-ɛ turbulence model, the heat transfer model and the acoustic model were used. According to the research results, the separation of the air stream in individual fan sections contributes to the improvement of energy efficiency and reduces noise emissions. As a result of the simulation, it was found that the best solution in terms of noise emission as well as the occurring flow phenomena caused about a 2 dB decrease of maximum values of the noise level and allowed the equalization of the cooling medium velocity (prevailing velocity range between 4 and 9 m/s). The results of the simulations were verified under laboratory and field conditions, showing a very good convergence of the model with the results of the experiments (i.e. the maximum noise level was estimated at 57 dB, under measurement conditions for the same operating point at 59 dB) while maintaining the baseline energy demand, which indicates a new approach in the method of shaping internal elements of electric vehicle coolers.

Internal combustion engine diagnostics using statistically processed Wiebe function

Famfulik Jan, Richtar Michal, Smiraus Jakub, Muckova Petra, Sarkan Branislav, Dresler Pavel

Eksploatacja i Niezawodność

2021

Vol. 23, no. 3

505--511

The aim of the article is to present the concept of an indirect diagnostic method using the assessment of the variability of the amount of released heat (mass fraction burn) and the heat release rate. The Wiebe function for the assessment of variability has been used. The Wiebe function parameters from the course of the high-pressure indication in the cylinder of internal combustion engine using linear regression have been calculated. From a sufficiently large number of measured samples, the upper and lower limits of the Wiebe function parameters have been statistically determined. Lower and upper limits characterize variability of the heat release process not only in terms of quantity but also in terms of heat release rate. The assessment of variability is thus more complicated than using one integral indicator, typically the mean value of amount of the released heat. The procedure enabling a more accurate estimation of heat generation beginning has been shown. For the combustion process variability assessment of the engine, statistical test of relative frequencies has been used.

Kryteria projektowania alternatorów samochodowych

Sęk A., Bogusz R.

Przegląd Elektrotechniczny

2011

R. 87, nr 3

243-248

W artykule przedstawiamy podstawowe kryteria projektowania alternatorów samochodowych oraz szczególne rozwiązania pozwalające na optymalizację konstrukcji w kierunku ich realizacji. Rozważane są: obliczenia własnego modelu, redukcja rozmiarów i masy, modyfikacja obwodu magnetycznego wzbudzenia (zmiana rozmiaru szczeliny powietrznej), poprawa efektywności chłodzenia, zmniejszenie anego hałasu i inne.

In this paper, we present basic criteria, as well as special solutions, permitting on optimalization of construction in direction their realization designing automotive altemators. Own model calculations, reduction in mass and size, modifications in the magnetic excitation circuit (air gap size change), improvement in the cooling efficiency, decrease of the generating noise and others are discussed.