scholarly journals The effect of seasonal weather changes on the performance of databased models of the thermodynamic behaviour of buildings

2020 ◽  
Vol 172 ◽  
pp. 02005
Author(s):  
Thea Hauge Broholt ◽  
Louise Rævdal Lund Christensen ◽  
Michael Dahl Knudsen ◽  
Rasmus Elbæk Hedegaard ◽  
Steffen Petersen
Keyword(s):  
Residential Buildings ◽  
Model Performance ◽  
Black Box ◽  
Box Model ◽  
Weather Data ◽  
Thermal Mass ◽  
Heating Season ◽  
Satisfactory Model ◽  
Weather Changes ◽  
Seasonal Weather

Several studies have indicated that Model Predictive Control (MPC) of space heating systems can utilize the thermal mass of residential buildings as short-term thermal storage for various demand response purposes. Realization of this potential relies heavily on the accuracy of the model used to represent the thermodynamics of the building. Such models, whether they are grey box or black box, are calibrated using relevant data obtained from initial measurements, and the performance of the calibrated model is validated using data from a subsequent period. However, many studies use validation periods with weather conditions similar to those of the calibration period. Only a few studies investigate whether the calibrated model performs satisfactory when subjected to significantly different conditions. This paper presents data from a simulation-based study on the effect of seasonal weather changes on the performance of a black-box model. The study was conducted using 11 years of Danish weather data (2008-2018). The results indicate that the performance of the black-box model deteriorate as the weather data conditions become increasingly different from those used in the initial model calibration. Further, the results show that calibration in heating season leads to satisfactory model performance through the heating season, but lower performance in transitional seasons (especially spring). Results also show that calibration in February led to highest model performance through heating season, while calibration in March led to satisfactory model performance in the whole heating and fall season.

Simulation Model of the Dynamic Behavior of a Tire Running Over an Obstacle

1988 ◽  
Vol 16 (2) ◽  
pp. 62-77 ◽  
Author(s):  
P. Bandel ◽  
C. Monguzzi
Keyword(s):  
Simulation Model ◽  
Dynamic Behavior ◽  
Black Box ◽  
Box Model ◽  
Vehicle Suspension ◽  
Empirical Relationships ◽  
Static Tests ◽  
High Speeds ◽  
Dynamic Forces ◽  
Vehicle Suspension System

Abstract A “black box” model is described for simulating the dynamic forces transmitted to the vehicle hub by a tire running over an obstacle at high speeds. The tire is reduced to a damped one-degree-of-freedom oscillating system. The five parameters required can be obtained from a test at a given speed. The model input is composed of a series of empirical relationships between the obstacle dimensions and the displacement of the oscillating system. These relationships can be derived from a small number of static tests or by means of static models of the tire itself. The model can constitute the first part of a broader model for description of the tire and vehicle suspension system, as well as indicating the influence of tire parameters on dynamic behavior at low and medium frequencies (0–150 Hz).

scholarly journals The Effect of the Thermal Mass of the Building Envelope on Summer Overheating of Dwellings in a Temperate Climate

Energies ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4117
Author(s):  
Tadeusz Kuczyński ◽  
Anna Staszczuk ◽  
Piotr Ziembicki ◽  
Anna Paluszak
Keyword(s):  
Building Materials ◽  
Heat Waves ◽  
Residential Buildings ◽  
Building Envelope ◽  
Temperate Climate ◽  
Maximum Temperature ◽  
Thermal Mass ◽  
Occupant Behavior ◽  
Average Maximum ◽  
Night Ventilation

The main objective of this paper is to demonstrate the effectiveness of increasing the thermal capacity of a residential building by using traditional building materials to reduce the risk of its excessive overheating during intense heat waves in a temperate climate. An additional objective is to show that the use of this single passive measure significantly reduces the risk of overheating in daytime rooms, but also, though to a much lesser extent, in bedrooms. Increasing the thermal mass of the room from light to a medium heavy reduced the average maximum daily temperature by 2.2K during the first heat wave and by 2.6K during the other two heat waves. The use of very heavy construction further reduced the average maximum temperature for the heat waves analyzed by 1.4K, 1.2K and 1.7K, respectively, giving a total possible reduction in maximum daily temperatures in the range of 3.6 °C, 3.8 °C and 4.3 °C. A discussion of the influence of occupant behavior on the use of night ventilation and external blinds was carried out, finding a significant effect on the effectiveness of the use of both methods. The results of the study suggest that in temperate European countries, preserving residential construction methods with heavy envelopes and partitions could significantly reduce the risk of overheating in residential buildings over the next few decades, without the need for night ventilation or external blinds, whose effectiveness is highly dependent on individual occupant behavior.

scholarly journals MFPP: Morphological Fragmental Perturbation Pyramid for Black-Box Model Explanations

2021 ◽  
Author(s):  
Qing Yang ◽  
Xia Zhu ◽  
Jong-Kae Fwu ◽  
Yun Ye ◽  
Ganmei You ◽  
...  
Keyword(s):  
Black Box ◽  
Box Model

scholarly journals Synchronous Machine Winding Modeling Method Based on Broadband Characteristics

2021 ◽  
Vol 11 (10) ◽  
pp. 4631
Author(s):  
Yu Chen ◽  
Xiaoqing Ji ◽  
Zhongyong Zhao
Keyword(s):  
Equivalent Circuit ◽  
High Frequency ◽  
Equivalent Circuit Model ◽  
Black Box ◽  
Synchronous Machine ◽  
Circuit Model ◽  
Modeling Method ◽  
Experimental Results ◽  
Box Model ◽  
Impedance Curve

The accurate establishment of the equivalent circuit model of the synchronous machine windings’ broadband characteristics is the basis for the study of high-frequency machine problems, such as winding fault diagnosis and electromagnetic interference prediction. Therefore, this paper proposes a modeling method for synchronous machine winding based on broadband characteristics. Firstly, the single-phase high-frequency lumped parameter circuit model of synchronous machine winding is introduced, then the broadband characteristics of the port are analyzed by using the state space model, and then the equivalent circuit parameters are identified by using an optimization algorithm combined with the measured broadband impedance characteristics of port. Finally, experimental verification and comparison experiments are carried out on a 5-kW synchronous machine. The experimental results show that the proposed modeling method identifies the impedance curve of the circuit parameters with a high degree of agreement with the measured impedance curve, which indicates that the modeling method is feasible. In addition, the comparative experimental results show that, compared with the engineering exploratory calculation method, the proposed parameter identification method has stronger adaptability to the measured data and a certain robustness. Compared with the black box model, the parameters of the proposed model have a certain physical meaning, and the agreement with the actual impedance characteristic curve is higher than that of the black box model.

scholarly journals Variable Link Performance Due to Weather Effects in a Long-Range, Low-Power LoRa Sensor Network

Sensors ◽  
2021 ◽  
Vol 21 (9) ◽  
pp. 3128
Author(s):  
Thomas Ameloot ◽  
Patrick Van Torre ◽  
Hendrik Rogier
Keyword(s):  
Sensor Networks ◽  
Low Power ◽  
Sensor Network ◽  
Link Quality ◽  
Long Distance ◽  
Received Power ◽  
Link Performance ◽  
Weather Changes ◽  
Minimal Power Consumption ◽  
Seasonal Weather

When aiming for the wider deployment of low-power sensor networks, the use of sub-GHz frequency bands shows a lot of promise in terms of robustness and minimal power consumption. Yet, when deploying such sensor networks over larger areas, the link quality can be impacted by a host of factors. Therefore, this contribution demonstrates the performance of several links in a real-world, research-oriented sensor network deployed in a (sub)urban environment. Several link characteristics are presented and analysed, exposing frequent signal deterioration and, more rarely, signal strength enhancement along certain long-distance wireless links. A connection is made between received power levels and seasonal weather changes and events. The irregular link performance presented in this paper is found to be genuinely disruptive when pushing sensor-networks to their limits in terms of range and power use. This work aims to give an indication of the severity of these effects in order to enable the design of truly reliable sensor networks.

CYBERNETIC MODEL IN PLANNING AND FORECASTING

2020 ◽  
Author(s):  
D.S. Serebryanaya ◽  
Keyword(s):  
Higher Education ◽  
Building Materials ◽  
Black Box ◽  
Box Model ◽  
Sociological Research ◽  
Mathematical Approach ◽  
Cybernetic Model ◽  
Corrective Measures

This article analyzes the mathematical approach to the study of the motives of students to study in higher education. The possibility of using the “black box” model used in the production of building materials for sociological research is considered. This approach allows you to see the most significant causes of discrepancies and develop corrective measures for them.

Investigation of Black Box Model for Erbium-Doped Fiber Amplifiers in Space Radiation Environment

2012 ◽  
Vol 30 (23) ◽  
pp. 3667-3671 ◽  
Author(s):  
Mi Li ◽  
Jing Ma ◽  
Xuping Zhang ◽  
Yuejiang Song ◽  
Wenhe Du
Keyword(s):  
Space Radiation ◽  
Black Box ◽  
Fiber Amplifiers ◽  
Box Model ◽  
Radiation Environment ◽  
Erbium Doped ◽  
Space Radiation Environment

scholarly journals Issues relating to the efficient application of passive solar protection in multi-family residential buildings

2020 ◽  
pp. 1-16
Author(s):  
Justyna Kobylarczyk ◽  
Janusz Marchwiński ◽  
Katarzyna Zielonko-Jung
Keyword(s):  
Energy Savings ◽  
Residential Buildings ◽  
Thermal Mass ◽  
Functional Specificity ◽  
Characteristic Functional ◽  
Spatial Features ◽  
Venetian Blinds ◽  
Building Facades ◽  
Solar Control ◽  
External Conditions

The following article is intended to discuss the issues concerning the introduction of passive measures aimed at improving solar protection in multi-family buildings. A system of classifying these methods into two groups of solutions (architectural and material-building) was applied. The first group includes issues concerning facade design, the spatial features of which (such as loggias, balconies and other overhangs) can be treated as one of the solar protection methods. The authors’ own studies are presented and expressed in a sequence of formulas. The formulas enable assessment of the effectiveness of the above elements, depending on external conditions. As far as the second group is concerned, material-construction solutions for building facades and roofs are discussed. The solutions mentioned include solar-control glazing, spatial shading elements (such as venetian blinds, roller blinds), roof and façade vegetation, and the thermal mass of the building. The essence of the functioning of the analysed solutions in relation to the characteristic functional specificity of multi-family buildings is discussed. Problematic areas of application of the above methods are indicated. As shown in the study, problematic areas may include a group of utilitarian-operating, economic and aesthetic issues, in the case of which the use of passive solutions encounters limitations. In conclusion, the possibilities for alleviating these limitations are highlighted. The authors’ own solutions presented in the following paper can contribute to energy savings and may thus prove beneficial for environmental reasons, thereby serving the aims of sustainable development.

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