scholarly journals Fitting new constructal models for the thermal potential of earth-air heat exchangers

2018 ◽  
Vol 40 (1) ◽  
pp. 30897 ◽  
Author(s):  
Jairo Valões de Alencar Ramalho ◽  
Ruth Da Silva Brum ◽  
Luiz Alberto Oliveira Rocha ◽  
Liércio André Isoldi ◽  
Elizaldo Domingues dos Santos ◽  
...  
Keyword(s):  
Heat Exchangers ◽  
Design Method ◽  
Global Constraints ◽  
Additional Contribution ◽  
Constructal Design ◽  
Thermal Potential ◽  
Periodic Models ◽  
Energetic Performance ◽  
Isosceles Triangles

 Relying on the Constructal Design method, this paper introduces new periodic models for the thermal potential of Earth-Air Heat Exchangers (Eahe). As a case study, it analyses the best spacing for three ducts arranged triangularly in order to maximize the heat transfer between soil and air. More specifically, the ratio  between the horizontal and vertical spaces among the ducts is set free to vary up to limiting global constraints. This paper aims to better understand how the variations in  affect the thermal performance of Eahe. As an additional contribution, some relationships between  and the thermal potential of Eahe are mathematically and continuously stated. This allows establishing additional results for the efficiency and energetic performance of Eahe, as well as recommend arrangements in the shape of isosceles triangles with base and height unitary. 

Numerical investigation about the improvement of the thermal potential of an Earth-Air Heat Exchanger (EAHE) employing the Constructal Design method

2015 ◽  
Vol 80 ◽  
pp. 538-551 ◽  
Author(s):  
Michel Kepes Rodrigues ◽  
Ruth da Silva Brum ◽  
Joaquim Vaz ◽  
Luiz Alberto Oliveira Rocha ◽  
Elizaldo Domingues dos Santos ◽  
...  
Keyword(s):  
Heat Exchanger ◽  
Numerical Investigation ◽  
Design Method ◽  
Constructal Design ◽  
Thermal Potential

On the Design of Two EAHE Assemblies with Four Ducts

2017 ◽  
Vol 372 ◽  
pp. 31-39 ◽  
Author(s):  
R.S. Brum ◽  
M.K. Rodrigues ◽  
J.V.A. Ramalho ◽  
Luiz Alberto Oliveira Rocha ◽  
Liércio André Isoldi ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Thermal Performance ◽  
Thermal Efficiency ◽  
Heat Exchangers ◽  
Design Method ◽  
Three Dimensional ◽  
Temperature Fields ◽  
Dimensional Model ◽  
Three Dimensional Model ◽  
Constructal Design

This article applies the constructal design method to analyze how to improve the thermal performance of earth-air heat exchangers (EAHE) composed by four ducts. The paper evaluates two types of arrangements for which the centers of the ducts take the shape of rectangles and diamonds. Under volumetric constraints, the vertical Sv and horizontal Sh spacings between the ducts are left free to vary. The objective is to maximize the magnitude of the EAHE instantaneous thermal potential P which is an average of the differences between the temperatures at the ducts outlets and inlets at any instant of time. The temperature fields are computed through numerical simulations, adopting a verified and validated three-dimensional model. Among the results, this work shows how the design can raise by 11% the annual thermal efficiency of the EAHE.

PERANCANGAN SISTEM PEMBELAJARAN MOBILE (M-LEARNING) BERBASIS ANDROID PADA MATERI BANGUN DATAR DAN BANGUN RUANG

2018 ◽  
Vol 1 (2) ◽  
pp. 1-17
Author(s):  
Tedi Budiman
Keyword(s):  
Mobile Learning ◽  
Design Method ◽  
Case Study Method ◽  
Application Development ◽  
Software Application ◽  
Rapid Application Development ◽  
User Design ◽  
Design Software ◽  
Application Programs

One example of the growing information technology today is mobile learning, mobile learning which refers to mobile technology as a learning medium. Mobile learning is learning that is unique for each student to access learning materials anywhere, anytime. Mobile learning is suitable as a model of learning for the students to make it easier to get an understanding of a given subject, such as math is pretty complicated and always using formulas.The design method that I use is the case study method, namely, learning, searching and collecting data related to the study. While the development of engineering design software application programs that will be used by the author is the method of Rapid Application Development (RAD), which consists of 4 stages: Requirements Planning Phase, User Design Phase, Construction Phase and Phase Cotuver.

Design and Evaluation of Usable Systems

2002 ◽  
Vol 46 (3) ◽  
pp. 367-371
Author(s):  
John F. McGrew
Keyword(s):  
Genetic Algorithm ◽  
Change Management ◽  
Management System ◽  
Design Method ◽  
The Other ◽  
Design Team ◽  
Style Analysis ◽  
Decision Style ◽  
Parallel Design

This paper discusses a case study of a design and evaluation of a change management system at a large Telecommunications Corporation. The design and evaluation were done using the facilitated genetic algorithm (a parallel design method) and user decision style analysis. During the facilitated genetic algorithm the design team followed the procedure of the genetic algorithm. Usability was evaluated by applying user decision style analysis to the designed system. The design is compared with an existing system and with one designed by an analyst. The change management system designed by the facilitated genetic algorithm took less time to design and decision style analysis indicated it would be easier to use than the other two systems.

Thermal Evaluation of Shell and Tube Heat Exchangers in the Sugar Industry: Case Study

Sugar Tech ◽  
2021 ◽  
Author(s):  
Thalyne de Almeida Ferreira Rocha ◽  
Altair Marques da Silva
Keyword(s):  
Heat Exchangers ◽  
Sugar Industry ◽  
Shell And Tube

The Unified Theory of Tubesheet Design - Part III: Comparison with ASME Method and Case Study

2021 ◽  
Author(s):  
Hong-Song Zhu ◽  
Jinguo Zhai ◽  
Guo-Yan Zhou
Keyword(s):  
Heat Exchangers ◽  
Numerical Comparison ◽  
Unified Theory ◽  
Element Analysis ◽  
Theoretical Comparison ◽  
Comparison Results ◽  
Different Types ◽  
Special Case ◽  
Simplified Mechanical Model

Abstract Based on the unified theory of tubesheet (TS) design for fixed TS heat exchangers (HEX), floating head and U-tube HEX presented in Part I and Part II, theoretical and numerical comparisons with ASME method are performed in this paper as Part III. Theoretical comparison shows that ASME method can be obtained from the special case of the simplified mechanical model of the unified theory. Numerical Comparison results indicate that predictions given by the unified theory agree well with finite element analysis (FEA), while ASME results are not accurate or not correct. Therefore, it is concluded that the unified theory deals with different types of HEX in equal detail with confidence to predict design stresses.

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