Formulation of the Reactor Thermal Hydraulic Design Problem

2021 ◽  
pp. 1-18
Author(s):  
Neil E. Todreas ◽  
Mujid S. Kazimi ◽  
Mahmoud Massoud
Keyword(s):  
Design Problem ◽  
Hydraulic Design

Design Problem Solving

2006 ◽  
Vol 214 (2) ◽  
pp. 73-86 ◽  
Author(s):  
Constance Winkelmann ◽  
Winfried Hacker
Keyword(s):  
Problem Solving ◽  
Design Problem

Zusammenfassung. In zwei experimentellen Studien werden mögliche alternative Bedingungen der lösungsgüteverbessernden Wirkung einer Frage-Antwort-Technik im Entwurfsdenken (Design Problem Solving) geprüft. In der ersten Studie (N = 84) wurden differential- und kognitionspsychologische Bedingungen geprüft. Eine Aussagenanalyse in einer zweiten Studie (N = 94) sollte die nachgewiesenen Ergebnisse vertiefen. Für die in beiden Studien ermittelten Lösungsgüteverbesserungen konnten keine differentialpsychologischen Abhängigkeiten von Vorgehensstilen nachgewiesen werden. In kognitionspsychologischer Hinsicht zeigte sich, dass sowohl Fragen, die die Forderungen der Aufgabe in Erinnerung bringen, als auch Fragen, deren Beantwortung die Auslösung von Denkprozessen fördern, zur Lösungsgüteverbesserung beitragen. Größere Effekte werden bei der Kombination beider Fragenarten nahe gelegt. Die Ergebnisse der Aussagenanalyse weisen auf eine sowohl beschreibende als auch begründende und bewertende Vorgehensweise der Untersuchungsteilnehmer hin, die Verbesserungen erzielten. Fragen für weiterführende Untersuchungserfordernisse werden abgeleitet.

Saline intrusion in deep riser outfall systems

1995 ◽  
Vol 32 (2) ◽  
pp. 175-182
Author(s):  
Roger A. Howard
Keyword(s):  
Physical Model ◽  
Recent Work ◽  
Saline Intrusion ◽  
Deep Tunnel ◽  
Hydraulic Design ◽  
Novel Methods

Saline intrusion can seriously affect the performance of outfall systems and an understanding of the mechanisms causing intrusion is important in the hydraulic design of outfalls, particularly for deep riser tunnelled outfalls. The paper outlines the reasons for the occurrence of saline intrusion, the problems that arise when it is present and the methods available for prevention and purging. The paper draws on recent work undertaken on the design of a major deep tunnel outfall system using a physical model and outlines some novel methods devised for purging of the system.

Theory and application of two-dimension viscous hydraulic design of the ultra-low specific-speed centrifugal pump

2019 ◽  
Vol 234 (1) ◽  
pp. 58-71 ◽  
Author(s):  
Cong Wang ◽  
Yongxue Zhang ◽  
Hucan Hou ◽  
Zhiyi Yuan
Keyword(s):  
Boundary Layer ◽  
Centrifugal Pump ◽  
Diagnostic Model ◽  
Two Dimension ◽  
Cavitation Performance ◽  
Hydraulic Design ◽  
Displacement Thickness ◽  
Low Specific Speed ◽  
Specific Speed ◽  
Low Efficiency

Low efficiency and bad cavitation performance restrict the development of the ultra-low specific-speed centrifugal pump (ULSSCP). In this research, combined turbulent boundary layer theory with two-dimension design and two-dimension viscous hydraulic design method has been proposed to redesign a ULSSCP. Through the solution of the displacement thickness in the boundary layer, a less curved blade profile with a larger outlet angle was obtained. Then the hydraulic and cavitation performance of the reference pump and the designed pump were numerically studied. The comparison of performance of the reference pump calculated by the numerical and experimental results revealed a better agreement. Research shows that the average hydraulic efficiency and head of the designed pump improve by 2.9% and 3.3%, respectively. Besides, the designed pump has a better cavitation performance. Finally, through the internal flow analysis with entropy production diagnostic model, a 24.8% drop in head loss occurred in the designed pump.

Boundary Condition Design to Heat a Moving Object at Uniform Transient Temperature Using Inverse Formulation

2004 ◽  
Vol 126 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Hakan Ertu¨rk ◽  
Ofodike A. Ezekoye ◽  
John R. Howell
Keyword(s):  
Boundary Condition ◽  
Temperature Distribution ◽  
Design Problem ◽  
Manufacturing Industry ◽  
Three Dimensional ◽  
Chemical Deposition ◽  
Iterative Solution ◽  
Conveyor Belt ◽  
Temperature History ◽  
Transient Temperature

The boundary condition design of a three-dimensional furnace that heats an object moving along a conveyor belt of an assembly line is considered. A furnace of this type can be used by the manufacturing industry for applications such as industrial baking, curing of paint, annealing or manufacturing through chemical deposition. The object that is to be heated moves along the furnace as it is heated following a specified temperature history. The spatial temperature distribution on the object is kept isothermal through the whole process. The temperature distribution of the heaters of the furnace should be changed as the object moves so that the specified temperature history can be satisfied. The design problem is transient where a series of inverse problems are solved. The process furnace considered is in the shape of a rectangular tunnel where the heaters are located on the top and the design object moves along the bottom. The inverse design approach is used for the solution, which is advantageous over a traditional trial-and-error solution where an iterative solution is required for every position as the object moves. The inverse formulation of the design problem is ill-posed and involves a set of Fredholm equations of the first kind. The use of advanced solvers that are able to regularize the resulting system is essential. These include the conjugate gradient method, the truncated singular value decomposition or Tikhonov regularization, rather than an ordinary solver, like Gauss-Seidel or Gauss elimination.

Optimal hydraulic design of an ultra-low specific speed centrifugal pump based on the local entropy production theory

2019 ◽  
Vol 233 (6) ◽  
pp. 715-726 ◽  
Author(s):  
Hucan Hou ◽  
Yongxue Zhang ◽  
Xin Zhou ◽  
Zhitao Zuo ◽  
Haisheng Chen
Keyword(s):  
Entropy Production ◽  
Centrifugal Pump ◽  
Orthogonal Design ◽  
High Energy ◽  
Geometrical Parameters ◽  
Production Theory ◽  
Local Entropy ◽  
Hydraulic Design ◽  
Low Specific Speed ◽  
Specific Speed

The ultra-low specific speed centrifugal pump has been widely applied in aerospace engineering, metallurgy, and other industrial fields. However, its hydraulic design lacks specialized theory and method. Moreover, the impeller and volute are designed separately without considering their coupling effect. Therefore, the optimal design is proposed in this study based on the local entropy production theory. Four geometrical parameters are selected to establish orthogonal design schemes including blade outlet setting angle, wrapping angle volute inlet width, and throat area. Subsequently, a 3D steady flow with Reynolds stress turbulent model and energy equation model is numerically conducted and the entropy production is calculated by a user-defined function code. The range analysis is made to identify the optimal scheme indicating that the combination of local entropy production and orthogonal design is feasible on pump optimization. The optimal pump is visibly improved with an increase of 1.08% in efficiency. Entropy production is decreased by 16.75% and 6.03% in impeller and volute, respectively. High energy loss areas are captured and explained in terms of helical vortex and wall friction, and the turbulent and wall entropy production are respectively reduced by 3.82% and 14.34% for the total pump.

scholarly journals Triple-Helix Structured Model Based on Problem-Knowledge-Solution Co-evolution for Innovative Product Design Process

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Qian Hui ◽  
Yan Li ◽  
Ye Tao ◽  
Hongwei Liu
Keyword(s):  
Product Design ◽  
Design Process ◽  
Design Problem ◽  
Triple Helix ◽  
Problem Solution ◽  
Innovative Product ◽  
Innovative Design ◽  
Structured Model ◽  
Knowledge Spaces ◽  
Product Design Process

AbstractA design problem with deficient information is generally described as wicked or ill-defined. The information insufficiency leaves designers with loose settings, free environments, and a lack of strict boundaries, which provides them with more opportunities to facilitate innovation. Therefore, to capture the opportunity behind the uncertainty of a design problem, this study models an innovative design as a composite solving process, where the problem is clarified and resolved from fuzziness to satisfying solutions by interplay among design problems, knowledge, and solutions. Additionally, a triple-helix structured model for the innovative product design process is proposed based on the co-evolution of the problem, solution, and knowledge spaces, to provide designers with a distinct design strategy and method for innovative design. The three spaces interact and co-evolve through iterative mappings, including problem structuring, knowledge expansion, and solution generation. The mappings carry the information processing and decision-making activities of the design, and create the path to satisfying solutions. Finally, a case study of a reactor coolant flow distribution device is presented to demonstrate the practicability of this model and the method for innovative product design.

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