scholarly journals NUMERICAL THERMAL MODEL OF AN INCANDESCENT LAMP FOR SATELLITES TESTING

2020 ◽  
pp. 50-58
Author(s):  
Dmitriy Kulikov ◽  
Keyword(s):  
Mathematical Modeling ◽  
Thermal Model ◽  
High Efficiency ◽  
Complex Problem ◽  
Thermal Design ◽  
Halogen Lamp ◽  
Quality Model ◽  
Good Convergence ◽  
The Monte Carlo Method ◽  
Model Generator

In the present article the author gives the results work to create a numerical thermal model of infrared (IR) emitter on the base of tubular halogen lamp (THL) KGT-220-1300, as one of the elements of the equipment used when conducting thermal vacuum tests (TVT) of satellites. As a tool to solve complex problem of heat transfer used software Thermal Model Generator. Variants of calculations for the operation of the lamp at different voltages are carried out. The results of mathematical modeling using band approximation of the properties of the system elements in combination with the Monte Carlo method in solving the problem of heat exchange by radiation showed high efficiency. The performed analysis of the correctness of the results showed good convergence with the data of previous experiments on measuring the temperature of the quartz bulb, which confirms the reliability of the results. Getting a high-quality model of this type at the disposal of satellite thermal engineer is an important step in the complex work aimed at conducting end-to-end mathematical modeling of satellite thermal design, and will also solve a number of issues related to the methodological support of TVT, their implementation and optimization.

scholarly journals Multidistribution Center Location Based on Real-Parameter Quantum Evolutionary Clustering Algorithm

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
Huaixiao Wang ◽  
Wanhong Zhu ◽  
Jianyong Liu ◽  
Ling Li ◽  
Zhuchen Yin
Keyword(s):  
Clustering Algorithm ◽  
High Efficiency ◽  
Real Parameter ◽  
The Real ◽  
Good Convergence ◽  
Evolutionary Clustering ◽  
Simulated Annealing Genetic Algorithm ◽  
Center Location ◽  
Fuzzy C Means Clustering ◽  
Fcm Clustering

To determine the multidistribution center location and the distribution scope of the distribution center with high efficiency, the real-parameter quantum-inspired evolutionary clustering algorithm (RQECA) is proposed. RQECA is applied to choose multidistribution center location on the basis of the conventional fuzzy C-means clustering algorithm (FCM). The combination of the real-parameter quantum-inspired evolutionary algorithm (RQIEA) and FCM can overcome the local search defect of FCM and make the optimization result independent of the choice of initial values. The comparison of FCM, clustering based on simulated annealing genetic algorithm (CSAGA), and RQECA indicates that RQECA has the same good convergence as CSAGA, but the search efficiency of RQECA is better than that of CSAGA. Therefore, RQECA is more efficient to solve the multidistribution center location problem.

scholarly journals Towards a Thermal Moore’s Law

2005 ◽  
Author(s):  
Shankar Krishnan ◽  
Suresh V. Garimella ◽  
Greg M. Chrysler ◽  
Ravi V. Mahajan
Keyword(s):  
Heat Sink ◽  
High Efficiency ◽  
Thermal Design ◽  
Air Cooling ◽  
Thermoelectric Coolers ◽  
Moore’S Law ◽  
Moore's Law ◽  
The Impact ◽  
Power Densities ◽  
Design Power

The thermal design power trends and power densities for present and future microprocessors are investigated. The trends are derived based on Moore’s law and scaling theory. Both active and stand-by power are discussed and accounted for in the calculations. A brief discussion of various leakage power components and their impact on the power density trends is provided. Two different lower limits of heat dissipation for irreversible logic computers are discussed. These are based on the irreversibility of logic to represent one bit of information, and on the distribution of electrons to represent a bit. These limits are found to be two or more orders of magnitude lower than present-day microprocessor thermal design power trends. Further, these trends are compared to the projected trends for the desktop product sector from the International Technology Roadmap for Semiconductors (ITRS). To evaluate the thermal impact of the projected power densities, heat sink thermal resistances are calculated for a given technology target. Based on the heat sink thermal resistance trends, the evolution of an air-cooling limit consistent with Moore’s law is predicted. One viable alternative to air-cooling, i.e., the use of high-efficiency solid-state thermoelectric coolers (TECs), is explored. The impact of different parasitics on the thermoelectric figure of merit (ZT) is quantified.   This paper was also originally published as part of the Proceedings of the ASME 2005 Heat Transfer Summer Conference.

An integrated model for high-speed motorized spindles – Dynamic behaviors

2013 ◽  
Vol 227 (11) ◽  
pp. 2467-2478 ◽  
Author(s):  
Xiao-an Chen ◽  
Jun-feng Liu ◽  
Ye He ◽  
Peng Zhang ◽  
Wen-tao Shan
Keyword(s):  
Dynamic Model ◽  
Heat Generation ◽  
Thermal Model ◽  
High Speed ◽  
High Efficiency ◽  
Solution Procedure ◽  
Integrated Model ◽  
Dynamic Behaviors ◽  
Dynamic Performances ◽  
Motorized Spindles

With increasing popularity in high-speed machining due to its high efficiency, there is a vital need for more accurate prediction of dynamic behaviors for high-speed motorized spindles. The spindle units integrate tools with built-in motors hence a comprehensive model is required to include the multi-physics coupling property. This article presents an integrated model which consists of four coupled sub-models: state, shaft, bearing, and thermal model. Using the variational principle, a state model for the motor-spindle system is generated, which can describe the running state of the spindle, and provide electrical parameters to study the motor heat generation for thermal model and the unbalanced magnetic force for shaft dynamic model. The thermal model is coupled with the bearing and shaft dynamic model through bearing heat generation and thermal displacement. Thus, the entire model becomes an integrated electro-thermo-mechanical dynamic model. The proposed integrated model is investigated by a solution procedure and validated experimentally, and it shows that the model is capable of accurately predicting the dynamic behaviors of motorized spindles. The coupling relationship among the electrical, thermal, and mechanical behaviors of the system becomes clear from the simulation and experimental results, and some feasible methods to improve the dynamic performances of the system are obtained.

A Detailed Study of the Interaction Between Two Rows of Cooling Holes

2018 ◽  
Vol 140 (4) ◽  
Author(s):  
Y. Jiang ◽  
L. Capone ◽  
P. Ireland ◽  
E. Romero
Keyword(s):  
Flat Plate ◽  
Film Cooling ◽  
High Efficiency ◽  
Nonlinear Effects ◽  
Suction Side ◽  
Complex Problem ◽  
Correct Prediction ◽  
Blowing Ratio ◽  
Key Factor ◽  
Plate Geometry

An optimal design of film cooling is a key factor in the effort of producing high-efficiency gas turbine. Understanding of the fluid dynamics interaction between cooling holes can help engineers to improve overall thermal effectiveness. Correct prediction through modeling is a very complex problem since multiple phenomena are involved such as mixing, turbulence, and heat transfer. The present work performs an investigation of different cooling configurations ranging from single hole up to two rows. The main objective is to evaluate the double-rows interaction and the effect on film cooling. Strong nonlinear effects are underlined by different simulations, while varying blowing ratio (BR) and geometrical configuration of cooling holes. Meanwhile an initial analysis is performed using flat plate geometry, verification and validation is then extended to realistic stage of high pressure (HP) turbine. Multiple cooling holes configurations are embedded on the pressure side (PS) and suction side (SS) of the single stage. The main outcome is the verification of the thermal effectiveness improvement obtained by cooling jets interaction of multiple rows design. The effects of curvature surface and frame of reference rotation are also evaluated, underlying the differences with standard flat plate test cases.

Thermal Design of a Hierarchical Radially Expanding Cavity for Two-Phase Cooling of Integrated Circuits

2015 ◽  
Author(s):  
Arvind Sridhar ◽  
Chin Lee Ong ◽  
Stefan Paredes ◽  
Bruno Michel ◽  
Thomas Brunschwiler ◽  
...  
Keyword(s):  
Design Process ◽  
Thermal Model ◽  
Thermal Design ◽  
Design Flow ◽  
Qualitative Description ◽  
System Level ◽  
Two Phase ◽  
Ongoing Research ◽  
Level Pressure ◽  
Phase Liquid

A major challenge in the implementation of evaporative two-phase liquid-cooled ICs with embedded fluid microchannels/cavities is the high pressure drops arising from evaporation-induced expansion and acceleration of the flowing two-phase fluid in small hydraulic diameters. Our ongoing research effort addresses this challenge by utilizing a novel hierarchical radially expanding channel networks with a central embedded inlet manifold and drainage at the periphery of the chip stack. This paper presents a qualitative description of the thermal design process that has been adopted for this radial cavity. The thermal design process first involves construction of a system-level pressure-thermal model for the radial cavity based on both fundamental experiments as well as numerical simulations performed on the building block structures of the final architecture. Finally, this system-level pressure-thermal model can be used to identify the design space and optimize the geometry to maximize thermal performance, while respecting design specifications. This design flow presents a good case study for electrical-thermal co-design of two-phase liquid cooled ICs.

Transient and Steady-State Thermal Design Evaluation of a Carbon Monoxide Gas Sensor Using CFD Tool

1998 ◽  
Vol 120 (2) ◽  
pp. 135-140 ◽  
Author(s):  
T.-Y. Tom Lee ◽  
R. Sharma ◽  
A. Peyre-Lavigne
Keyword(s):  
Carbon Monoxide ◽  
Gas Sensor ◽  
Thermal Model ◽  
Chemical Sensor ◽  
Low Cost ◽  
Complex Structure ◽  
Temperature Response ◽  
Thermal Design ◽  
High And Low Temperatures ◽  
Sensor Package

This paper summarizes thermal modeling work performed on the Motorola Carbon Monoxide (CO) chemical sensor. Gas sensors need low cost reliable packages, good thermal operation, and low power consumption. The goal is to provide a validated thermal model of a gas sensor and its package and to develop a sensor design capability with reduced design cycle time. Due to the complex structure of the sensor package, a computational fluid dynamics (CFD) tool was used to analyze the heat transfer and fluid flow within the package. Based on the validated model, parametric studies on filter location and package orientation were performed. In order to minimize the influence of humidity, the sensor is toggled between high and low temperatures by applying 5 volts for 5 s of heating, and 1 volt for 10 s of cooling. Transient thermal analysis was also performed to predict the temperature response of various components. A detailed description of the thermal model and its results are described in the paper.

The MS 5002E: A New 2-Shaft, High Efficiency Heavy Duty Gas Turbine for Oil and Gas Applications

2001 ◽  
Author(s):  
Luca Aurelio ◽  
Paolo Battagli ◽  
Dino Bianchi ◽  
Arlie R. Martin ◽  
Leonardo Tognarelli
Keyword(s):  
Firing Temperature ◽  
Oil And Gas ◽  
High Efficiency ◽  
State Of The Art ◽  
Pressure Ratio ◽  
High Heat ◽  
Combined Cycle ◽  
Thermal Design ◽  
Heavy Duty ◽  
Cycle Efficiency

In mid-’98 it was decided to develop a new high efficiency version of the very successful MS5002 (GE Frame 5 two-shaft), to satisfy the most recent Customer requirements in terms of fuel consumption and environmental impact. The machine was conceived considering different markets, primarily mechanical drive, but also non-Oil&Gas power generation. Power class is 30 MW, pressure ratio is 17:1, simple cycle efficiency is over 36% and combined cycle efficiency approximately 51%. The new model retains features that contributed to the success of its predecessors. The main ones are the full heavy-duty concept for on-site maintenance, the moderate firing temperature (compared with state of the art) for highest reliability, the two-shaft design with free power turbine for mechanical drive use, the high heat recovery capability. Achievement of high cycle efficiency with low firing temperature is possible thanks the advanced tools used for the definition, design and optimization of airfoils, clearances, leakages and distribution of cooling flows. Aero-thermal design was largely based on state of the art 3D CFD and on sophisticated airfoil cooling techniques of the same type extensively used in aircraft engine development. The dry-low-emissions combustion system design is derived from the GEPS DLN2.6. A thorough testing program, including the full-scale test of the axial compressor and a full load prototype test, is planned to support development and to validate the design.

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