scholarly journals Towards an algorithmic synthesis of thermofluid systems

2020 ◽  
Author(s):  
Jonas B. Weber ◽  
Michael Hartisch ◽  
Alexander D. Herbst ◽  
Ulf Lorenz
Keyword(s):  
Heat Transfer ◽  
Design Process ◽  
Practical Experience ◽  
Point Of View ◽  
Fluid Distribution ◽  
Develop Model ◽  
Mathematical Methods ◽  
High Rise ◽  
Fluid Systems ◽  
Technical Systems

Abstract Individual technical components are usually well optimized. However, the design process of entire technical systems, especially in its early stages, is still dominated by human intuition and the practical experience of engineers. In this context, our vision is the widespread availability of software tools to support the human-driven design process with the help of modern mathematical methods. As a contribution to this, we consider a selected class of technical systems, so-called thermofluid systems. From a technical point of view, these systems comprise fluid distribution as well as superimposed heat transfer. Based on models for simple fluid systems as extensively studied in literature, we develop model extensions and algorithmic methods directed towards the optimized synthesis of thermofluid systems to a practical extent. Concerning fluid systems, we propose a Branch-and-Bound framework, exploiting problem-specific characteristics. This framework is then further analyzed using the application example of booster stations for high-rise buildings. In addition, we demonstrate the application of Quantified Programs to meet possible resilience requirements with respect to the systems generated. In order to model basic thermofluid systems, we extend the existing formulation for fluid systems by including heat transfer. Since this consideration alone is not able to deal with dynamic system behavior, we face this challenge separately by providing a more sophisticated representation dealing with the temporal couplings that result from storage components. For the considered case, we further show the advantages of this special continuous-time representation compared to the more common representation using discrete time intervals.

scholarly journals Multifunctional Cantilevers as Working Elements in Solid-State Cooling Devices

Actuators ◽  
2021 ◽  
Vol 10 (3) ◽  
pp. 58
Author(s):  
Andraž Bradeško ◽  
Lovro Fulanović ◽  
Marko Vrabelj ◽  
Aleksander Matavž ◽  
Mojca Otoničar ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Ethylene Glycol ◽  
Contact Resistance ◽  
High Efficiency ◽  
Thermal Contact ◽  
Point Of View ◽  
Practical Implementation ◽  
Cooling Devices ◽  
Cascade Structure ◽  
Lead Magnesium

Despite the challenges of practical implementation, electrocaloric (EC) cooling remains a promising technology because of its good scalability and high efficiency. Here, we investigate the feasibility of an EC cooling device that couples the EC and electromechanical (EM) responses of a highly functionally, efficient, lead magnesium niobate ceramic material. We fabricated multifunctional cantilevers from this material and characterized their electrical, EM and EC properties. Two active cantilevers were stacked in a cascade structure, forming a proof-of-concept device, which was then analyzed in detail. The cooling effect was lower than the EC effect of the material itself, mainly due to the poor solid-to-solid heat transfer. However, we show that the use of ethylene glycol in the thermal contact area can significantly reduce the contact resistance, thereby improving the heat transfer. Although this solution is most likely impractical from the design point of view, the results clearly show that in this and similar cooling devices, a non-destructive, surface-modification method, with the same effectiveness as that of ethylene glycol, will have to be developed to reduce the thermal contact resistance. We hope this study will motivate the further development of multifunctional cooling devices.

Multicriterial Optimization of Technical Systems Considering Multiple Load and Availability Scenarios

2015 ◽  
Vol 807 ◽  
pp. 247-256 ◽  
Author(s):  
Lena C. Altherr ◽  
Thorsten Ederer ◽  
Philipp Pöttgen ◽  
Ulf Lorenz ◽  
Peter F. Pelz
Keyword(s):  
System Design ◽  
Cost Effective ◽  
Optimization Methods ◽  
Technical System ◽  
Multicriterial Optimization ◽  
Fluid Systems ◽  
Rule Number ◽  
Technical Systems ◽  
Multiple Load ◽  
Modern Optimization

Cheap does not imply cost-effective -- this is rule number one of zeitgeisty system design. The initial investment accounts only for a small portion of the lifecycle costs of a technical system. In fluid systems, about ninety percent of the total costs are caused by other factors like power consumption and maintenance. With modern optimization methods, it is already possible to plan an optimal technical system considering multiple objectives. In this paper, we focus on an often neglected contribution to the lifecycle costs: downtime costs due to spontaneous failures. Consequently, availability becomes an issue.

scholarly journals The Metano Modeling Toolbox MMTB: An Intuitive, Web-Based Toolbox Introduced by Two Use Cases

Metabolites ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 113
Author(s):  
Julia Koblitz ◽  
Sabine Will ◽  
S. Riemer ◽  
Thomas Ulas ◽  
Meina Neumann-Schaal ◽  
...  
Keyword(s):  
Metabolic Networks ◽  
Point Of View ◽  
Use Cases ◽  
Mathematical Methods ◽  
State Behavior ◽  
Web Based ◽  
Research Fields ◽  
Balance Analysis ◽  
Metabolic Models ◽  
User Friendly

Genome-scale metabolic models are of high interest in a number of different research fields. Flux balance analysis (FBA) and other mathematical methods allow the prediction of the steady-state behavior of metabolic networks under different environmental conditions. However, many existing applications for flux optimizations do not provide a metabolite-centric view on fluxes. Metano is a standalone, open-source toolbox for the analysis and refinement of metabolic models. While flux distributions in metabolic networks are predominantly analyzed from a reaction-centric point of view, the Metano methods of split-ratio analysis and metabolite flux minimization also allow a metabolite-centric view on flux distributions. In addition, we present MMTB (Metano Modeling Toolbox), a web-based toolbox for metabolic modeling including a user-friendly interface to Metano methods. MMTB assists during bottom-up construction of metabolic models by integrating reaction and enzymatic annotation data from different databases. Furthermore, MMTB is especially designed for non-experienced users by providing an intuitive interface to the most commonly used modeling methods and offering novel visualizations. Additionally, MMTB allows users to upload their models, which can in turn be explored and analyzed by the community. We introduce MMTB by two use cases, involving a published model of Corynebacterium glutamicum and a newly created model of Phaeobacter inhibens.

scholarly journals Color Response Modification of Encapsulated Liquid Crystals Used in Rotating Disk Heat Transfer Studies

1995 ◽  
Author(s):  
Cengiz Camci ◽  
Boris Glezer
Keyword(s):  
Heat Transfer ◽  
Liquid Crystal ◽  
Liquid Crystals ◽  
Rotational Speed ◽  
Rotating Disk ◽  
Point Of View ◽  
Centrifugal Acceleration ◽  
Relative Shift ◽  
Color Response ◽  
Stationary Conditions

The liquid crystal thermography can be successfully used in both transient and steady-state heat transfer experiments with excellent spatial resolution and good accuracy. Although most of the past liquid crystal based heat transfer studies are reported in the stationary frame, measurements from the rotating frame of turbomachinery systems exist The main objective of the present investigation is to determine the influence of rotation on the color calibration of encapsulated liquid crystals sprayed on the flat surface of a rotating aluminum disk. The investigation is performed for a rotational speed range from 0 rpm to 7500 rpm using three different liquid crystal coatings displaying red at 30, 35 and 45° C, under stationary conditions. An immediate observation from the present study is that the color response of liquid crystals is strongly modified by the centrifugal acceleration of the rotating environment. It is consistently and repeatedly observed that the hue versus temperature curve is continuously shifted toward lower temperatures by increasing rotational speed. The relative shift of the display temperature of the green can be as high as 7°C at 7500 rpm when compared to the temperature of the green observed under stationary conditions. The present study shows that relative shift of the liquid crystal color has a well-defined functional dependency to rotational speed. The shift is linearly proportional to the centrifugal acceleration. It is interesting to note that the individual shift curves of the green for all three liquid crystal coatings collapse into a single curve when they are normalized with respect to their own stationary green values. When the color attribute is selected as “intensity” instead of “hue”, very similar shifts of the temperature corresponding to the intensity maximum value appearing around green is observed. An interpretation of the observed color shift is made from a thermodynamics energy balance point of view.

Heat Transfer and Thermal Stress Analysis of an Optoelectronic Package

1991 ◽  
Vol 113 (3) ◽  
pp. 258-262 ◽  
Author(s):  
J. G. Stack ◽  
M. S. Acarlar
Keyword(s):  
Heat Transfer ◽  
Thermal Management ◽  
Power Dissipation ◽  
Point Of View ◽  
Optical Data ◽  
Data Link ◽  
Element Analysis ◽  
Thermally Induced ◽  
Temperature Changes ◽  
Induced Stresses

The reliability and life of an Optical Data Link transmitter are inversely related to the temperature of the LED. It is therefore critical to have efficient packaging from the point of view of thermal management. For the ODL® 200H devices, it is also necessary to ensure that all package seals remain hermetic throughout the stringent military temperature range requirements of −65 to +150°C. For these devices, finite element analysis was used to study both the thermal paths due to LED power dissipation and the thermally induced stresses in the hermetic joints due to ambient temperature changes

Warm-up as part of a training session

2021 ◽  
pp. 89-98
Author(s):  
Е.И. Чучкалова ◽  
О.Г. Маскина
Keyword(s):  
Higher Education ◽  
Training Session ◽  
Practical Experience ◽  
Structural Features ◽  
Educational Process ◽  
Point Of View ◽  
Educational Organizations ◽  
Business Training ◽  
Warm Up ◽  
Teachers And Students

Статья посвящена организации учебного процесса в высшей школе. Авторы, в частности, считают, что лекционные и практические занятия должны начинаться и заканчиваться разминкой, подразумевающей выполнение коротких упражнений. С помощью специально проведенного исследования в работе анализируются структурные особенности учебных разминок, уточняются их отличия от бизнес-разминок, применяемых в ходе тренингов, а также рассматривается с содержательной и организационной точек зрения специфика применения разминок в высшей школе. Выводы сделаны с учетом мнения преподавателей и студентов, уже имеющих опыт участия в разминках. Научная новизна публикации заключается в расширении представлений о возможностях, которые открываются при использовании разминок в учебном процессе. В статье проведена их классификация по различным критериям: виду активности, массовости, желаемому результату, формату проведения. Кроме того, автор обобщил собственный практический опыт использования инструментов бизнес-тренингов, накопленный в ходе подготовки бакалавров и магистрантов, привел примеры наиболее популярных упражнений в каждой группе матрицы разминок. Особое внимание уделено разминкам, сопровождающим вебинары, что продолжает оставаться чрезвычайно актуальным в свете современного перехода на смешанный формат обучения в профессиональном образовании. Статья предназначена для преподавателей и студентов высших и средних профессиональных образовательных организаций. The article focuses on the organization of the educational process in higher education. The author, in particular, believes that lectures and practical classes should begin and end with a warm-up, which implies doing short exercises. With the help of specially conducted research, the paper analyzes the structural features of training warm-ups, clarifies their differences from business warm-ups used during training, and also considers the specifics of using warm-ups in higher education from a substantive and organizational point of view. The conclusions are made considering the opinions of teachers and students who already have experience of doing warm-ups. The scientific novelty of the publication lies in bringing better understanding of the opportunities that open up with using warm-ups in the educational process. The article classifies them according to various criteria: the type of activity, mass character, the desired result, the format of the event. In addition, the author summarized his own practical experience of using business training tools during the preparation of bachelors and undergraduates gave examples of the most popular exercises in each group of the warm-up matrix. Special attention is paid to the warm-ups accompanying webinars, which continues to be extremely relevant in the light of the modern transition to a mixed format of training in vocational education. The article is intended for teachers and students of higher and secondary professional educational organizations.

Practical experience in the technical systems creating with the artificial intelligence elements

2021 ◽  
Vol 26 (jai2021.26(1)) ◽  
pp. 95-101
Author(s):  
Pisarenko V ◽  
◽  
Pisarenko J ◽  
Gulchak O ◽  
Chobotok T ◽  
...  
Keyword(s):  
Artificial Intelligence ◽  
Extreme Environments ◽  
Practical Experience ◽  
Mine Safety ◽  
Technical Equipment ◽  
Rescue Work ◽  
Safety Control ◽  
Artificial Brain ◽  
Technical Systems ◽  
The Creation

The practical experience of solving scientific tasks using artificial intelligence technologies is presented. The authors offered their understanding of the term "artificial intelligence". Describes the development of the dept. №265 of Mathematical Problems of Applied Informatics V.M. Glushkov Institute of Cybernetics of the NAS of Ukraine in the creation of technical systems with elements of AI mainly to work in extreme environments. The purpose of the authors is to provide useful information to develop a strategy for the development of AI in the Ukraine. Some of these studies: monitoring the territory and management of land use technologies using remote sensing technologies from aircraft, spacecraft, unmanned aerial vehicles; monitoring the technical equipment of the underwater environment (technical means of searching for a sunken object of the submarine type for emergency operations are being developed); mine safety control (risk research during mining, creating robotic systems with elements of artificial intelligence for studying the conditions of work in the mine, warning accidents and emergency rescue work). The next direction is the diagnosis and treatment of addictive patients using the principles of therapeutic methods BiofeedBack. Attention is paid to the development of robotic technical systems with AI for servicing cosmic long missions. For this, theoretical studies have been conducted on the creation of a live brain mathematical model for its use in the development of the "artificial brain" of robots. The authors gave a list of tasks that can solve AI in programs for long-term space flights, technologies and systems that should develop in the first place to implement these tasks

scholarly journals Design Process of Energy Effective Shredding Machines for Biomass Treatment

10.14311/1622 ◽  
2012 ◽  
Vol 52 (5) ◽  
Author(s):  
Juraj Beniak ◽  
Juraj Ondruška ◽  
Viliam Čačko
Keyword(s):  
Energy Consumption ◽  
Energy Saving ◽  
Design Process ◽  
Electric Energy ◽  
Point Of View ◽  
Processed Material ◽  
Material Saving

The shredding process has not been sufficiently investigated for the design of better, energy and material saving shredding machines. In connection with present-day concern about the environment, ecology, energy saving, recycling, and finding new sources of energy, we need to look at the design of shredding machinery, the efficiency of the machines that we using, and ways of improving them to save electric energy for their operation. This paper deals with sizing and designing shredding machines from the point of view of energy consumption and optimization for specific types of processed material.

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