scholarly journals Development and Application of a Thermal Comfort Model in Buildings

2022 ◽  
Vol 7 ◽  
pp. 1
Author(s):  
Andrés Vilaboa Díaz ◽  
Pastora M. Bello Bugallo
Keyword(s):  
Mathematical Model ◽  
Thermal Comfort ◽  
Thermal Inertia ◽  
Design Parameters ◽  
System Response ◽  
Thermal Mass ◽  
The European Union ◽  
External Temperature ◽  
Temperature Variations ◽  
The Mathematical Model

Buildings are one of the systems that more energy consumed in the European Union. The study of the thermal envelope is interesting in order to reduce the energy losses. For that, a mathematical model able to predict the system response to external temperature variations is developed. With the mathematical model, different thermal envelope elements of a building based on the lag and the cushioning of the resultant wave can be characterized. In addition, it is important to analyse where the insulation is placed, because when the insulation is outside and the thermal mass is inside, the system produces a response with smooth temperature variations than when the insulation is inside. Therefore, placing the outside insulation generates more steady indoor temperatures, increasing the thermal comfort inside the building. To complete the mathematical model that allows predicting the temperature inside a building taking into account the solar inputs and the thermal inertia of the building. This study will help to establish the optimum design parameters in order to build sustainable and comfortable buildings. Furthermore, it will take one step forward in the construction of nearly Zero-Energy Buildings.

Mobile Worm-Like Robots for Pipe Inspection

2015 ◽  
pp. 168-218 ◽  
Author(s):  
Sergey Fedorovich Jatsun ◽  
Andrei Vasilevich Malchikov
Keyword(s):  
Mathematical Model ◽  
Control System ◽  
Mobile Robots ◽  
Experimental Studies ◽  
Design Parameters ◽  
Robot Motion ◽  
Robot Dynamics ◽  
Confined Space ◽  
Pipe Inspection ◽  
The Mathematical Model

This chapter describes various designs of multilink mobile robots intended to move inside the confined space of pipelines. The mathematical model that describes robot dynamics and controlled motion, which allows simulating different regimes of robot motion and determining design parameters of the device and its control system, is presented. The chapter contains the results of numerical simulations for different types of worm-like mobile robots. The experimental studies of the in-pipe robots prototypes and their analyses are presented in this chapter.

scholarly journals Research on Chaos Response of the Nonlinear Vibration System of Giant Magnetostrictive Actuator

2020 ◽  
Vol 2020 ◽  
pp. 1-14
Author(s):  
Hongbo Yan ◽  
Yu Niu ◽  
Hong Gao ◽  
Hongbo Hao
Keyword(s):  
Mathematical Model ◽  
Amplitude Spectrum ◽  
Experimental Simulation ◽  
System Response ◽  
Threshold Condition ◽  
Vibration System ◽  
Chaotic Response ◽  
Magnetostrictive Actuator ◽  
Excitation Force ◽  
The Mathematical Model

In the present study, the chaotic response of the nonlinear magnetostrictive actuator (GMA) vibration system is investigated. The mathematical model of the nonlinear GMA vibration system is established according to J-A hysteresis nonlinear model, quadratic domain rotation model, Newton’s third law, and principle of GMA structural dynamics by analyzing the working principle of GMA. Then, the Melnikov function method is applied to the threshold condition of the chaotic response of the system to obtain the sense of Smale horseshoe transformation. Furthermore, the mathematical model is solved to investigate the system response to the excitation force and frequency. Accordingly, the corresponding displacement waveform, phase plane trajectory, Poincaré map, and amplitude spectrum are obtained. The experimental simulation is verified using Adams software. The obtained results show that the vibration equation of the nonlinear GMA vibration system has nonlinear and complex motion characteristics with different motion patterns. It is found that the vibration characteristics of the system can be controlled through adjusting the excitation force and frequency.

scholarly journals Influence of building orientation on internal temperature in saharan climates, building located in Ghardaïa region (Algeria)

2013 ◽  
Vol 17 (2) ◽  
pp. 349-364 ◽  
Author(s):  
Sidi Bekkouche ◽  
Tayeb Benouaz ◽  
Mohamed Cherier ◽  
Maamar Hamdani ◽  
Mohamed Yaiche ◽  
...  
Keyword(s):  
Thermal Comfort ◽  
Thermal Insulation ◽  
Air Temperature ◽  
Thermal Inertia ◽  
Numerical Data ◽  
Internal Temperature ◽  
And Control ◽  
The Mathematical Model ◽  
Do So

In desert regions, the orientation of buildings has an important influence in the inside air temperature. In the present work, we carry out a study on the influence of the buildings orientation as well as the thermal insulation on the internal temperature. To do so, we have considered the case where only the exposed walls are isolated. The main objective of the current work is to determine the temperatures of the building in question with and without thermal insulation. This study aims at assessing also the geographic parameter enhancing or damping the role of thermal inertia, providing a variety of results. As result, this work proves that stones play a contradictory role on thermal comfort. We have verified that thermal insulation is specified to reduce heat transfer through the building. Concerning the orientation, results indicates that the variation in orientation does not influence significantly the internal air temperature of a well thermally insulated building. Moreover, in hot period, whatever orientation considered, the phenomenon of overheating presents a serious problem to minimize consumption of energy and control of indoor temperature in case of building without insulation. The numerical data was compared to the experimental measurements in order to validate the mathematical model. In conclusion, to achieve a better thermal comfort arid and semi arid regions, the habitation will have to be situated in south flan of a hill to satisfy the two strategies (hot and cold).

scholarly journals Parametric Method For Evaluating Optimal Ship Deadweight

2014 ◽  
Vol 21 (2) ◽  
pp. 3-8
Author(s):  
Jan P. Michalski
Keyword(s):  
Mathematical Model ◽  
Closed Form ◽  
Parametric Method ◽  
Freight Rate ◽  
Ship Design ◽  
Design Parameters ◽  
Optimal Value ◽  
Simplifying Assumptions ◽  
The Mathematical Model ◽  
Economic Measure

Abstract The paper presents a method of choosing the optimal value of the cargo ships deadweight. The method may be useful at the stage of establishing the main owners requirements concerning the ship design parameters as well as for choosing a proper ship for a given transportation task. The deadweight is determined on the basis of a selected economic measure of the transport effectiveness of ship - the Required Freight Rate (RFR). The mathematical model of the problem is of a deterministic character and the simplifying assumptions are justified for ships operating in the liner trade. The assumptions are so selected that solution of the problem is obtained in analytical closed form. The presented method can be useful for application in the pre-investment ships designing parameters simulation or transportation task studies.

Engineering Constraint Management Based on an Occurrence Matrix Approach

1993 ◽  
Vol 115 (1) ◽  
pp. 103-109 ◽  
Author(s):  
R. Agrawal ◽  
G. L. Kinzel ◽  
R. Srinivasan ◽  
K. Ishii
Keyword(s):  
Mathematical Model ◽  
Degrees Of Freedom ◽  
Inequality Constraints ◽  
Design Parameters ◽  
Constraint Management ◽  
Management Concepts ◽  
Occurrence Matrix ◽  
Torsion Bar ◽  
The Mathematical Model ◽  
Management Algorithms

In many mechanical systems, the mathematical model can be characterized by m nonlinear equations in n unknowns. The m equations could be either equality constraints or active inequality constraints in a constrained optimization framework. In either case, the mathematical model consists of (n-m) degrees of freedom, and (n-m) unknowns must be specified before the system can be analyzed. In the past, designers have often fixed the set of (n-m) specification variables and computed the remaining n variables using the n equations. This paper presents constraint management algorithms that give the designer complete freedom in the choice of design specifications. An occurrence matrix is used to store relationships among design parameters and constraints, to identify dependencies among the variables, and to help prevent redundant specification. The interactive design of a torsion bar spring is used to illustrate constraint management concepts.

scholarly journals Desempeño térmico de cerramientos de tierra alivianada Posibilidades de aplicación en el territorio peruano

2019 ◽  
Vol 22 (1) ◽  
Author(s):  
Martín Wieser-Rey ◽  
Silvia Onnis ◽  
Giuseppina Meli
Keyword(s):  
Thermal Comfort ◽  
Thermal Inertia ◽  
Thermal Mass ◽  
Thermal Transmittance ◽  
Qualitative And Quantitative ◽  
Palabras Clave ◽  
Energy Efficiency Standard ◽  
Thermal Simulations ◽  
Passive Air Conditioning

Resumen Las soluciones constructivas tradicionales y contemporáneas han demostrado tener serias limitaciones en la solución del déficit cualitativo y cuantitativo de la vivienda y el equipamiento, de igual manera, las evidencias del desempeño térmico son igualmente desalentadoras. Es por lo que se indaga sobre la capacidad de la tierra alivianada de brindar confort térmico en los edificios, considerando los diferentes climas del territorio peruano y comparándola con los sistemas constructivos más comunes en el medio: el adobe y la albañilería de ladrillo. A partir de la caracterización previa de las cualidades térmicas de los componentes y de la realización de simulaciones térmicas dinámicas, comparando el desempeño de diferentes prototipos digitales, se identificaron las virtudes de la tierra alivianada por el marcado equilibrio entre una masa térmica media y una conductividad térmica relativamente baja, siendo los únicos que logran cumplir con las exigencias de la actual norma peruana de eficiencia energética para el caso de los climas más fríos. Adicionalmente de destaca la composición a partir de materiales naturales, renovables y biodegradables que son ventajas ecológicas. Palabras clave: arquitectura bioclimática; arquitectura sostenible; climatización pasiva; confort térmico; inercia térmica; simulación térmica; sistema constructivo; transmitancia térmica   Abstract Traditional and contemporary construction systems have shown serious limitations in the solution of the qualitative and quantitative deficit of housing and equipment, in the same way, the evidence of thermal performance is equally discouraging. That is why we inquire about the ability of the land relieved to provide thermal comfort in buildings, considering the different climates of the Peruvian territory and comparing it with the most common construction systems in the environment: adobe and brick masonry. From the previous characterization of the thermal qualities of the components and the realization of dynamic thermal simulations, comparing the performance of different digital prototypes, the virtues of the earth alleviated by the marked balance between a medium thermal mass and a conductivity were identified relatively low thermal, being the only ones that manage to meet the requirements of the current Peruvian energy efficiency standard in the case of colder climates. In addition, the composition from natural, renewable and biodegradable materials that are ecological advantages stands out. Keywords: bioclimatic architecture; sustainable architecture; passive air conditioning; Thermal comfort; thermal inertia; thermal simulation; construction system; thermal transmittance.   Recibido: febrero 25 / 2019  Evaluado: septiembre 20 / 2019  Aceptado: noviembre 23 / 2019 Publicado en línea: noviembre de 2019                               Actualizado: noviembre de 2019  

scholarly journals MATHEMATICAL AND PHYSICAL BASIS FOR DEVELOPING A SIMULATOR FOR TOWING AND PULLING OF WHEELED AND TRACKED MACHINES

2021 ◽  
Vol 5 (4) ◽  
pp. 135-139
Author(s):  
Alexander Serhieiev ◽  
Andriy Krivoshapka ◽  
Oleksandr Isakov ◽  
Vyacheslav Lysenko ◽  
Viktor Moskalenko ◽  
...  
Keyword(s):  
Mathematical Model ◽  
Physical Basis ◽  
Design Parameters ◽  
System Of Equations ◽  
Aramid Fibers ◽  
Tracked Vehicles ◽  
General Scientific ◽  
And Performance ◽  
The Mathematical Model ◽  
Physical Quantities

The subject matter of the article is the towing and pulling of wheeled and tracked vehicles with the use of cable ropes and dynamic slings. The goal of the study is to determine the mathematical and physical basis for the development of a simulator for towing and pulling wheeled and tracked vehicles for researching to study the possibility of using aramid fibers of cable-ropes and dynamic slings. The tasks to be solved are: based on the analysis of the main roads and ground characteristics to formalize the list of calculated parameters and physical quantities determine the amount of evacuation work when pulling, towing and transporting wheeled and tracked vehicles; to develop a mathematical model that describes the process of pulling and towing wheeled and tracked vehicles using cable ropes and dynamic slings. General scientific and special methods of scientific knowledge are used. The following results are obtained. By analyzing the main characteristics of roads and ground, a formalized list of design parameters and physical quantities that determine the volume of evacuation work during the towing and pulling of wheeled and tracked vehicles was obtained. Mathematical model, describes the process of pulling and towing wheeled and tracked machines using cable ropes and dynamic slings have been  compiled as a system of equations with different order. analyzed existing technology for the production of aramid fibers, their strengths and weaknesses, and formed a research polygon with regard to the peculiarities of the operation of wheeled and tracked vehicles. Existing technology for the production of aramid fibers, their strengths and weaknesses, and formed a research polygon with regard to the peculiarities of the operation of wheeled and tracked vehicles have been analyzed. Conclusions. The main roads and ground characteristics  that determine the vehicles. evacuation conditions are the following: the type of road or ground, their possibility depending on the season and precipitation, the presence of ascents and descents, as well as the nature of road (ground) interaction with caterpillars determined by resistance coefficients. movement and traction. The mathematical model of pulling a wheeled and tracked vehicle using cable ropes and dynamic can be presented as a system of equations: the jerk carried out by the machine in time reflected third-order differential equation, assuming that all the energy accumulated by the cable is numerically equal to the work of moving stuck machine, corresponds to the equality of the corresponding integrals; the properties of aramid fibers that affect the strength and performance characteristics of cable ropes can be formally expressed through the elongation of the cable. Analysis of strength and service properties of aramid fibers opens the way to improvement of manufacturing technology of cable ropes and dynamic slings for pulling and towing of wheeled and tracked vehicles.

Computerized Tooth Profile Generation and Undercut Analysis of Gears Manufactured With Pre-Shaving Hobs

2009 ◽  
Vol 16-19 ◽  
pp. 1278-1282
Author(s):  
Xiang Wei Kong ◽  
Jing Zhang ◽  
Meng Hua Niu
Keyword(s):  
Mathematical Model ◽  
Computer Program ◽  
Gear Tooth ◽  
Tooth Profile ◽  
Design Parameters ◽  
Gear Teeth ◽  
The Mathematical Model

This paper investigated the feature of pre-shaving hob contour and the generated gear tooth profile. By tooth generation method, a complete geometry of the gear tooth can be mathematically derived in terms of the design parameters of the pre-shaving hob cutter. The mathematical model consisted of equations describing the generated fillet and involute profiles. The degree of undercutting and the radii of curvatures of a fillet were investigated by considering the model. Finally, a computer program for generating the profile of the gear teeth was developed by simulating the cutting methods. The methods proposed in this study were expected to be a valuable guidance for pre-shaving hob designers and manufacturers.

scholarly journals Mathematical model and geometrical design method of noncircular face gear with intersecting axes

2021 ◽  
pp. 095440622199070
Author(s):  
Dawei Liu ◽  
Zhenzhen Lv ◽  
Bingbing Li
Keyword(s):  
Mathematical Model ◽  
Fourier Series ◽  
Design Method ◽  
Experimental Results ◽  
Transmission Mechanism ◽  
Design Parameters ◽  
Cnc Milling ◽  
Face Gear ◽  
Pitch Curve ◽  
The Mathematical Model

In order to establish the design method of a noncircular face gear (NFG) with intersecting axes, the meshing theory of this gear is investigated based on the principle of space gear meshing. A generalized approach for designing closed pitch curve of the NFG with intersecting axes was proposed based on Fourier series. The mathematical model of the NFG generated by a shaper cutter was established. The fundamental design parameters of the gears were defined, with the principle for determining their values discussed. The prototype of a NFG was machined by 5-axis CNC milling and the motion rule was tested. Experimental results verify the feasibility of the innovative transmission mechanism and the correctness of the mathematical model of NFG with intersecting axes.

scholarly journals Development of the mathematical model for the process of oil raw materials pressing

2018 ◽  
Vol 7 (2.13) ◽  
pp. 145
Author(s):  
Ainura Kairbayeva ◽  
Vitalii Vasilenko ◽  
Seit Dzhinguilbayev ◽  
Lyazzat Baibolova ◽  
Larisa Frolova
Keyword(s):  
Mathematical Model ◽  
Chemical Interaction ◽  
Raw Materials ◽  
Screw Press ◽  
Design Stage ◽  
Design Parameters ◽  
Single Screw ◽  
Porous Skeleton ◽  
The Mathematical Model ◽  
Oil Filtration

The mathematical model for the process of oily raw materials pressing with single-screw oil press has been developed, which makes it possible to calculate the main design parameters of an oil press for extracting oil from oil crop seeds.This model of pressing describes the process of moving meal in the pressure zone and expression of oil in the pressing cage of the screw press, taking into account the following assumptions: porous skeleton and oil have the same density, they have no chemical interaction, the process of oil filtration occurs under isothermal conditions with laminar conditions of motion.The developed mathematical model corresponds to physical meaning of the occurring phenomena and can be used to analyze the work of active presses, and at the design stage. 

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