Compact Thermal and System Modeling of Chip-Scale Pyroelectric Infrared Imager

2007 ◽  
Author(s):  
Brian Smith ◽  
Cristina Amon
Keyword(s):  
System Modeling ◽  
Three Dimensional ◽  
System Model ◽  
Thermal Mass ◽  
Specific System ◽  
Thermal Models ◽  
Sensor Material ◽  
Infrared Imager ◽  
Transient Thermal ◽  
Thermal Phenomena

The performance of pyroelectric infrared detectors is directly related to the ability of the sensor material to retain infrared energy (heat) incident from the source and to react fast to changing heat loads. This leads to a complicated, three dimensional, transient thermal models when many detectors are assembled into an infrared focal plane array (IRFPA) for thermal imaging. Adjacent pixels and the underlying substrate conduct heat away from the sensor material and add thermal mass to the system. This paper describes efforts and drawbacks in deriving a system model to capture thermal phenomena in a candidate IRFPA. Of particular interest is the tradeoff between cumbersome finite element models (long solve time, complicated meshes) and a reduced-size RC network circuit model that is simple to solve and integrate with the electrical design but may not capture the full thermal behavior of the system adequately. The thermal models are cast in terms of the operating principles of pyroelectric devices to describe a full electrical-thermal system model that adapts existing literature in the field to the specific system described in this work.

scholarly journals Human-Centered Design Using System Modeling Language

2017 ◽  
Vol 11 (3) ◽  
pp. 252-269 ◽  
Author(s):  
Michael E. Watson ◽  
Christina F. Rusnock ◽  
John M. Colombi ◽  
Michael E. Miller
Keyword(s):  
System Design ◽  
System Modeling ◽  
System Model ◽  
Modeling Language ◽  
Specific System ◽  
Human Centered Design ◽  
Common System ◽  
External Actors

The human user is important to consider during system design. However, common system design models, such as the system modeling language, typically represent human users and operators as external actors, rather than as internal to the system. This research presents a method for integrating human considerations into system models through human-centered design. A specific system is selected to serve as the case study for demonstrating the methodology. The sample system is analyzed to identify the task and information flow. Then, both system- and human-centered diagrams are separately created to represent different viewpoints of the system. These diagrams are compared and analyzed, and new diagrams are created that incorporate both system and human considerations into one concordant representation of the system model. These new views allow systems engineers and human factors engineers to effectively communicate the role of the user during early system design trades.

A 3-D Vision System Model for Automatic Object Surface Sensing

1992 ◽  
Author(s):  
Vassilios E. Theodoracatos ◽  
Dale E. Calkins
Keyword(s):  
Vision System ◽  
System Modeling ◽  
Three Dimensional ◽  
System Model ◽  
Average Error ◽  
Geometrical Parameters ◽  
Affine Transformations ◽  
Reconstruction Process ◽  
System Sensitivity ◽  
Surface Sensing

Abstract The development of a “light striping” (structured light) based three-dimensional vision system for automatic surface sensing is presented. The three-dimensional world-point reconstruction process and system modeling methodology involves homogeneous coordinate transformations applied in two independent stages; the video imaging stage using three-dimensional perspective transformations, and the mechanical scanning stage, using three-dimensional affine transformations. Concatenation of the two independent matrix models leads to a robust four-by-four matrix system model. The independent treatment of the two-dimensional imaging process from the three-dimensional modeling process, has reduced the number of unknown internal and external geometrical parameters. The reconstructed sectional contours (light stripes) are automatically and in real-time registered with respect to a common world coordinate system in a format compatible with B-spline surface approximation. The reconstruction process is demonstrated by measuring the surface of a 19.5-ft long by 2 feet beam rowing shell. A detailed statistical accuracy and precision analysis shows an average error, 0.2 percent (0.002), of an object’s largest dimension within the the camera’s field-of-view. System sensitivity analysis reveals a nonlinear increase for angles between the normals of the image and laser planes higher than 45 degrees.

scholarly journals Effects of operating and material parameters on the thermal characteristics of a wet clutch

2021 ◽  
Vol 13 (7) ◽  
pp. 168781402110341
Author(s):  
Zhigang Zhang ◽  
Ling Zou ◽  
Hang Liu ◽  
Yonglong Chen ◽  
Benzhu Zhang
Keyword(s):  
Heat Flux ◽  
Applied Pressure ◽  
Thermal Characteristics ◽  
Thermal Models ◽  
Material Parameters ◽  
Heat Transfer Theory ◽  
Friction Disk ◽  
Viscous Shear ◽  
Wet Clutch ◽  
Transient Thermal

Based on the frictional mechanism of a wet clutch, frictional models of wet clutch engagement were established using the modified Reynolds equation and the elastic contact model between frictional pairs. Then, the heat flux models for the viscous shear and asperity friction were built, and the two-dimensional transient thermal models for the separator plate, friction disk, and ATF heat convection model were deduced based on the heat transfer theory and conservation law of energy. Finally, the Runge–Kutta numerical method was used to solve the frictional and thermal models. The average temperature of the separator plate, friction disk, and ATF were calculated. The effects of operating and material parameters, such as applied pressure, initial angular velocity, friction lining permeability, surface combined roughness RMS, equivalent elastic modulus, and ATF flow, on the thermal characteristics of friction pairs and ATF during engagement, were studied. The simulation results show that the temperature characteristics of the separator plate, friction disk, and ATF depend mainly on the viscous shear and asperity friction heat flux, and that the operating and material parameters of the wet clutch also have significant impacts on the overall variation trend of the thermal characteristics of the separator plate, friction disk, and ATF.

scholarly journals Transient Thermal Analysis of NH000 gG 100A Fuse Link Employing Finite Element Method

Energies ◽  
2021 ◽  
Vol 14 (5) ◽  
pp. 1421
Author(s):  
Michał Szulborski ◽  
Sebastian Łapczyński ◽  
Łukasz Kolimas ◽  
Łukasz Kozarek ◽  
Desire Dauphin Rasolomampionona ◽  
...  
Keyword(s):  
Finite Element Method ◽  
Finite Element ◽  
Ceramic Body ◽  
Three Dimensional ◽  
Operating Mode ◽  
Power Losses ◽  
Empirical Tests ◽  
Transient Thermal ◽  
Different Parts ◽  
Element Method

In this paper, a detailed three-dimensional, transient, finite element method of fuse link NH000 gG 100 A is proposed. The thermal properties during the operation of the fuses under nominal (100 A) and custom conditions (110 and 120 A) are the main focus of the analyses that were conducted. The work concerns both the outside elements of the fuse link (ceramic body) and the elements inside (current circuit). Both the distribution of the electric current and its impact on the temperature of the construction parts of the fuses during their operating mode have been described. Temperature distribution, power losses and energy dissipation were measured using a numerical model. In order to verify and validate the model, two independent teams of scientists executed experimental research, during which the temperature was measured on different parts of the device involving the rated current. Finally, the two sets of results were put together and compared with those obtained from the simulation tests. A possible significant correlation between the results of the empirical tests and the simulation work was highlighted.

The Study on Man-Machine System Modeling Based on Computer Aided Ergonomics Design

2012 ◽  
Vol 490-495 ◽  
pp. 2667-2671
Author(s):  
Jing Wang
Keyword(s):  
System Modeling ◽  
Three Dimensional ◽  
Machine System ◽  
Knowledge Repository ◽  
Structural Framework ◽  
Computer Aided

The article introduces the necessity and superiority of development of CAED. It elaborates the framework and composition of the knowledge repository of CAED system and puts forward the opinion of three-dimensional Man-machine system modeling, in which the crucial elements and methods of system modeling are stressed. Based on all these ideas, the structural framework of CAED system is presented

Transient Thermal Analysis for the Automotive Underhood and Underbody Components

2013 ◽  
Author(s):  
Yu Hsien Wu ◽  
Kumar Srinivasan ◽  
Steven Patterson ◽  
Emmanuel Bot
Keyword(s):  
Thermal Analysis ◽  
Thermal Management ◽  
Dissimilar Materials ◽  
Thermal Mass ◽  
New Approach ◽  
The Past ◽  
Full Vehicle ◽  
Development Cycle ◽  
Transient Thermal ◽  
Steady State Solutions

The transient thermal simulation is an important part of thermal management development for new vehicle architectures. Different techniques have been studied in the past to address this coupled conduction/convection/radiation problem. In order to fully capture the transient thermal behavior of various underhood and underbody components, it is also necessary to accurately model the thermal mass of each part and the thermal links between dissimilar materials. The paper will outline a new, efficient methodology for this type of thermal analysis that shows acceptable results for complex full vehicle thermal analysis without sacrificing accuracy. The methodology is based on approximating the transient convective field with intermittent steady state solutions. The paper will present results from this new approach and compare them with fully transient simulation results as well as experimental data. The new methodology can be optimized to significantly reduce simulation run times without sacrificing accuracy and to be more practical for application in the vehicle development cycle.

Computational Insights Into Air-Side Flow and Heat Transfer in Compact Heat Exchangers

2005 ◽  
Author(s):  
D. K. Tafti
Keyword(s):  
Heat Transfer ◽  
Heat Capacity ◽  
Heat Exchangers ◽  
Three Dimensional ◽  
Computer Experiments ◽  
Transfer Coefficients ◽  
Substantial Impact ◽  
Compact Heat Exchangers ◽  
Thermal Phenomena ◽  
Side Flow

The paper describes two- and three-dimensional computer simulations which are used to study fundamental flow and thermal phenomena in multilouvered fins used for air-side heat transfer enhancement in compact heat exchangers. Results pertaining to flow transition, thermal wake interference, and fintube junction effects are presented. It is shown that a Reynolds number based on flow path rather than louver pitch is more appropriate in defining the onset of transition, and characteristic frequencies in the louver bank scale better with a global length scale such as fin pitch than with louver pitch or thickness. With the aid of computer experiments, the effect of thermal wakes is quantified on the heat capacity of the fin as well as the heat transfer coefficient, and it is established that experiments which neglect accounting for thermal wakes can introduce large errors in the measurement of heat transfer coefficients. Further, it is shown that the geometry of the louver in the vicinity of the tube surface has a large effect on tube heat transfer and can have a substantial impact on the overall heat capacity.

scholarly journals An Evaluation and Implementation of the Regional Coupled Ice-Ocean Model of the Baltic Sea

2017 ◽  
Author(s):  
Jaromir Jakacki ◽  
Sebastian Meler
Keyword(s):  
Baltic Sea ◽  
Three Dimensional ◽  
Coupled Model ◽  
Horizontal Resolution ◽  
Ocean Model ◽  
System Model ◽  
The Baltic Sea ◽  
Community Earth System Model ◽  
The Baltic ◽  
Ice Model

Abstract. A three dimensional, regional coupled ice-ocean model based on the open-source Community Earth System Model has been developed and implemented for the Baltic Sea. The model consists of 66 vertical levels and has a horizontal resolution of approx. 2.3 km. The paper focuses on sea ice component results but the main changes have been introduced in the ocean part of the coupled model. The hydrodynamic part, being one of the most important components, has been also presented and validated. The ice model results were validated against the radar and satellite data, and the method of validation based on probability was introduced. In the last two decades satellite and model results show an increase in the ice extent over the whole Baltic Sea, which is an evidence of a negative trend in air temperature in recent decades and increasing of winter discharge from the catchment area.

scholarly journals МОДЕЛЬ ПРОЦЕСУ ВІДНОВЛЕННЯ ІНФОРМАЦІЇ З УШКОДЖЕНИХ НОСІЇВ

2018 ◽  
Vol 120 (2) ◽  
pp. 26-37
Author(s):  
В. Б. Швайченко ◽  
О. П. Гребінь ◽  
Н. Ф. Левенець
Keyword(s):  
Conceptual Model ◽  
System Modeling ◽  
Recovery Process ◽  
Sound Quality ◽  
Computer Processing ◽  
System Model ◽  
Information Recovery ◽  
Restoration Process ◽  
Processing Modes

Improving the quality of the restored information in the process of restoration and restoration of phonograms.Synthesis of the system model on the basis of analysis of the processes of restoration and restoration of phonograms from media of various types and computer processing. The characteristics of the conceptual model of the restoration and restoration of the phonogram are determined. The structure of the system model of the information recovery process is developed. A lot of concepts and connections between concepts are defined. The structure of the system modeling restoration and restoration of phonograms is defined. A conceptual model of the restoration and restoration process is proposed. The distribution of artifacts over the playback and processing modes of a phonogram is justified. Details of the type of content with features of the effect on the state of the phonogram.The solutions obtained are the basis of the methodology for carrying out the process of restoration and restoration of phonograms by the criterion of sound quality.

Sign in / Sign up

Export Citation Format

Share Document