A Formal Representation of Conjugate Verbs in Function Modeling

2020 ◽  
Author(s):  
Ahmed Chowdhury ◽  
Lakshmi N. A. Venkatanarasimhan ◽  
Chiradeep Sen
Keyword(s):  
Causal Reasoning ◽  
Operating Mode ◽  
Flow Property ◽  
System Level ◽  
Formal Representation ◽  
Geothermal Heat ◽  
Design Problems ◽  
Geothermal Heat Pump ◽  
Level Model ◽  
Function Models

Abstract Many modern and innovative design problems require multi-modal, reconfigurable solutions. Function modeling is a common tool used to explore solutions in early stages of mechanical engineering design. Currently, function structure representations do not support the modeling of formally-defined reconfigurable function models. There is a well-established need in function modeling to dynamically capture the effects of state change of a flow property on the operating mode of the system. This paper presents a formal representation to capture the duality of specific functions, and illustrates it through three verbs that shift from one mode of operation to its logical and topological opposite, based on the existence of, or the value of a signal from, an input flow. Additionally, an approach to extend these functions to function features, in order to support physics-based reasoning on the interactions between flows is also presented. Through the example of a system-level model of a geothermal heat pump operating in its heating mode, the representation demonstrates the ability to support causal reasoning on functional modes of systems, provides quantitative reasoning on the efficiency of those modes, and illustrates the modeling efficacy of the extended representation.

A Formal Representation of Conjugate Verbs for Function Modeling

2021 ◽  
pp. 1-34
Author(s):  
Ahmed Chowdhury ◽  
Lakshmi Narasimhon Athinarayana Venkatanarasimhan ◽  
Chiradeep Sen
Keyword(s):  
Mechanical Design ◽  
System Level ◽  
Formal Representation ◽  
Geothermal Heat ◽  
Operating Modes ◽  
Heating And Cooling ◽  
Geothermal Heat Pump ◽  
Level Function ◽  
Modal Reasoning ◽  
Functional Features

Abstract Modern design problems often require multi-modal, reconfigurable solutions. Function modeling is a common tool used to explore solutions in early mechanical design. Currently, function modeling formalisms minimally support the modeling of multi-modal systems in a formal manner. There is a need in function modeling to capture multi-modal system and analyze the effects of control signals and status signals on their operating modes. This paper presents the concept of functional conjugacy, where two function verbs or functional subgraphs are topological opposites of each other. The paper presents a formal representation of these conjugate verbs that formally captures the transition from one mode of operation to its topological opposite based on the existence of, or the value of, signal flows. Additionally, this paper extends functional conjugacy to functional features, which supports conjugacy-based reasoning at a higher level of abstraction. Through the example of a system-level function model of a geothermal heat pump operating in its heating and cooling modes, this paper demonstrates the ability to support modal reasoning on function models using functional conjugacy and illustrates the modeling efficacy of the extended representation.

Evaluation of heat exchange rate of GHE in geothermal heat pump systems

2009 ◽  
Vol 34 (12) ◽  
pp. 2898-2904 ◽  
Author(s):  
Liu Jun ◽  
Zhang Xu ◽  
Gao Jun ◽  
Yang Jie
Keyword(s):  
Exchange Rate ◽  
Heat Exchange ◽  
Heat Pump ◽  
Geothermal Heat ◽  
Geothermal Heat Pump

scholarly journals Dynamic modelling of a servo self-pierce riveting (SPR) process

2021 ◽  
pp. 095440542110374
Author(s):  
Daniel Tang ◽  
Mike Evans ◽  
Paul Briskham ◽  
Luca Susmel ◽  
Neil Sims
Keyword(s):  
Dynamic Modelling ◽  
System Level ◽  
Optimum Process ◽  
Current Limit ◽  
Level Model ◽  
System Level Model ◽  
Head Height ◽  
Extensive Experimental Data ◽  
High Level

Self-pierce riveting (SPR) is a complex joining process where multiple layers of material are joined by creating a mechanical interlock via the simultaneous deformation of the inserted rivet and surrounding material. Due to the large number of variables which influence the resulting joint, finding the optimum process parameters has traditionally posed a challenge in the design of the process. Furthermore, there is a gap in knowledge regarding how changes made to the system may affect the produced joint. In this paper, a new system-level model of an inertia-based SPR system is proposed, consisting of a physics-based model of the riveting machine and an empirically-derived model of the joint. Model predictions are validated against extensive experimental data for multiple sets of input conditions, defined by the setting velocity, motor current limit and support frame type. The dynamics of the system and resulting head height of the joint are predicted to a high level of accuracy. Via a model-based case study, changes to the system are identified, which enable either the cycle time or energy consumption to be substantially reduced without compromising the overall quality of the produced joint. The predictive capabilities of the model may be leveraged to reduce the costs involved in the design and validation of SPR systems and processes.

Modeling of a two-phase CO2-filled vertical borehole for geothermal heat pump applications

2014 ◽  
Vol 114 ◽  
pp. 611-620 ◽  
Author(s):  
Parham Eslami-Nejad ◽  
Mohamed Ouzzane ◽  
Zine Aidoun
Keyword(s):  
Heat Pump ◽  
Geothermal Heat ◽  
Two Phase ◽  
Geothermal Heat Pump ◽  
Vertical Borehole

Application of Meshless Pore-Level Model to Pyrolysis and Synthesis of Nuclear Fuels

2007 ◽  
Author(s):  
Xiaolin Wang ◽  
Hui Zhang ◽  
Lili Zheng
Keyword(s):  
Material Processing ◽  
Transport Phenomena ◽  
Nuclear Material ◽  
Processing Technique ◽  
System Level ◽  
Scale Model ◽  
Nuclear Fuels ◽  
Particle Hydrodynamics ◽  
Level Model ◽  
Pore Level

Uranium-ceramic nuclear fuels can be fabricated through pyrolysis-based materials processing technique. This technique requires lower energy compared to sintering route. During the fabrication process, the source material changes composition continuously and chemical reactions and transport phenomena vary accordingly. Therefore, to obtain such nuclear fuel materials with high uniformity of microstructure/species without crack, transport phenomena in the material processing needs to be better understood. A system-scale model has been developed to account for the pyrolysis-based uranium-ceramic nuclear material processing in our prior work. In this study, a pore-scale numerical model based on Smoothed Particle Hydrodynamics (SPH) will be described for modeling the synthesis of SiC matrix and U3O8. The system-level model provides thermal boundary conditions to the pore-level model. The microstructure and compositions of the produced composites will be studied. Since the control of process temperature plays an important role in the material quality, the effects of heating rate and U3O8 particle size and volume on species uniformity and microstructure are investigated.

A CFD-supported dynamic system-level model of a sodium-cooled billboard-type receiver for central tower CSP applications

Solar Energy ◽  
2019 ◽  
Vol 177 ◽  
pp. 576-594 ◽  
Author(s):  
M. Cagnoli ◽  
A. de la Calle ◽  
J. Pye ◽  
L. Savoldi ◽  
R. Zanino
Keyword(s):  
Dynamic System ◽  
System Level ◽  
Level Model ◽  
System Level Model

scholarly journals A techno-economic model for application of geothermal heat pump systems

2017 ◽  
Vol 142 ◽  
pp. 2611-2616 ◽  
Author(s):  
Seyed Ali Ghoreishi-Madiseh ◽  
Ali Fahrettin Kuyuk
Keyword(s):  
Heat Pump ◽  
Economic Model ◽  
Geothermal Heat ◽  
Geothermal Heat Pump
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