Simulations and Experimental Studies towards Thermal Performance Improvement of 36 kV Bushings

2020 ◽  
Vol 187 ◽  
pp. 106426
Author(s):  
Suat Ilhan ◽  
Ilim Erden ◽  
Aydogan Ozdemir
Keyword(s):  
Performance Improvement ◽  
Thermal Performance ◽  
Experimental Studies

CONVEYOR MODEL AND IMPLEMENTATION OF THE REAL NUMBERS ADDER ON FPGA

2020 ◽  
Vol 33 (109) ◽  
pp. 21-31
Author(s):  
І. Ya. Zeleneva ◽  
Т. V. Golub ◽  
T. S. Diachuk ◽  
А. Ye. Didenko
Keyword(s):  
Performance Improvement ◽  
Experimental Studies ◽  
Production Costs ◽  
Floating Point ◽  
Computing Device ◽  
Quartus Ii ◽  
Functional Blocks ◽  
Mental Testing ◽  
Processor Cores ◽  
Floating Point Numbers

The purpose of these studies is to develop an effective structure and internal functional blocks of a digital computing device – an adder, that performs addition and subtraction operations on floating- point numbers presented in IEEE Std 754TM-2008 format. To improve the characteristics of the adder, the circuit uses conveying, that is, division into levels, each of which performs a specific action on numbers. This allows you to perform addition / subtraction operations on several numbers at the same time, which increas- es the performance of calculations, and also makes the adder suitable for use in modern synchronous cir- cuits. Each block of the conveyor structure of the adder on FPGA is synthesized as a separate project of a digital functional unit, and thus, the overall task is divided into separate subtasks, which facilitates experi- mental testing and phased debugging of the entire device. Experimental studies were performed using EDA Quartus II. The developed circuit was modeled on FPGAs of the Stratix III and Cyclone III family. An ana- logue of the developed circuit was a functionally similar device from Altera. A comparative analysis is made and reasoned conclusions are drawn that the performance improvement is achieved due to the conveyor structure of the adder. Implementation of arithmetic over the floating-point numbers on programmable logic integrated cir- cuits, in particular on FPGA, has such advantages as flexibility of use and low production costs, and also provides the opportunity to solve problems for which there are no ready-made solutions in the form of stand- ard devices presented on the market. The developed adder has a wide scope, since most modern computing devices need to process floating-point numbers. The proposed conveyor model of the adder is quite simple to implement on the FPGA and can be an alternative to using built-in multipliers and processor cores in cases where the complex functionality of these devices is redundant for a specific task.

scholarly journals Experimental Investigation and Comparison of the Thermal Performance of Additively and Conventionally Manufactured Heat Exchangers

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 574
Author(s):  
Ana Vafadar ◽  
Ferdinando Guzzomi ◽  
Kevin Hayward
Keyword(s):  
Surface Roughness ◽  
Thermal Performance ◽  
Heat Exchangers ◽  
High Efficiency ◽  
Cooling System ◽  
Fluid Dynamic ◽  
Dynamic Performance ◽  
Experimental Studies ◽  
Manufacturing Method ◽  
Industrial Sectors

Air heat exchangers (HXs) are applicable in many industrial sectors because they offer a simple, reliable, and cost-effective cooling system. Additive manufacturing (AM) systems have significant potential in the construction of high-efficiency, lightweight HXs; however, HXs still mainly rely on conventional manufacturing (CM) systems such as milling, and brazing. This is due to the fact that little is known regarding the effects of AM on the performance of AM fabricated HXs. In this research, three air HXs comprising of a single fin fabricated from stainless steel 316 L using AM and CM methods—i.e., the HXs were fabricated by both direct metal printing and milling. To evaluate the fabricated HXs, microstructure images of the HXs were investigated, and the surface roughness of the samples was measured. Furthermore, an experimental test rig was designed and manufactured to conduct the experimental studies, and the thermal performance was investigated using four characteristics: heat transfer coefficient, Nusselt number, thermal fluid dynamic performance, and friction factor. The results showed that the manufacturing method has a considerable effect on the HX thermal performance. Furthermore, the surface roughness and distribution, and quantity of internal voids, which might be created during and after the printing process, affect the performance of HXs.

Thermal performance improvement of kerosene cook-stoves by heat reuse and radiant heat shielding

2018 ◽  
Vol 136 (4) ◽  
pp. 1847-1860 ◽  
Author(s):  
Howard O. Njoku ◽  
Ikenna N. Agbo ◽  
Izuchukwu P. Agwuna ◽  
Darlington I. Egeonu ◽  
Felix U. Asuquo ◽  
...  
Keyword(s):  
Performance Improvement ◽  
Thermal Performance ◽  
Radiant Heat ◽  
Cook Stoves ◽  
Heat Shielding

scholarly journals Performance improvement of the heat recovery unit with sequential type heat pipes using TiO2 nanofluid

2019 ◽  
Vol 23 (3 Part B) ◽  
pp. 1755-1764 ◽  
Author(s):  
Ahmet Ozturk ◽  
Mehmet Ozalp ◽  
Adnan Sozen ◽  
Metin Guru
Keyword(s):  
Thermal Performance ◽  
Heat Recovery ◽  
Experimental Studies ◽  
Heat Pipes ◽  
Outer Diameter ◽  
Distilled Water ◽  
Condenser Section ◽  
Recovery System ◽  
Heat Recovery System ◽  
Set Up

This paper deals with the improvement of thermal performance of the heat recovery system in air-to-air unit by using a nanofluid of TiO particles and distilled water. The 2 experimental set-up equipped with 15 copper pipes of a 1000 mm length, 10.5 mm inner diameter, and 12 mm outer diameter was used. The evaporator section consists of 450 mm of heat pipes, the condenser section is 400 mm, and the adiabatic section is 150 mm. In experimental studies, 33% of the evaporator volumes of heat pipes were filled with working fluids. Experiments were carried out at temperatures between 25?C and 90?C by using five different cooling air-flows (40, 42, 45, 61, and 84 g/s), and two different heating powers (3 kW and 6 kW) for the evaporation section, to determine heat removed from the condensation section. Trials were performed for distilled water and nanofluid respectively, and the results were compared with each other. Results revealed that a 50% recovery in the thermal performance of the heat pipe heat recovery system was achieved in the design using TiO nanofluid as the working liquid, at a heating power of 3 kW, air 2 velocity of 2.03 m/s and air-flow of 84 g/s.

Thermal Performance Improvement of a Heat Sink With Piezoelectric Vibrating Fins

2010 ◽  
Author(s):  
Hee Seung Park ◽  
Sung Jin Kim
Keyword(s):  
Natural Frequency ◽  
Performance Improvement ◽  
Thermal Performance ◽  
Vibration Frequency ◽  
Heat Sink ◽  
Vibration Amplitude ◽  
Piezoelectric Actuators ◽  
Convection Heat ◽  
Heat Transfer Characteristics ◽  
Heat Sink Temperature

A heat sink with piezoelectric vibrating fins is developed through attaching piezoelectric actuators to the fins of a heat sink, and the heat transfer characteristics of the heat sink are experimentally investigated. Thermal performance improvement of the heat sink by the vibration of the fins is observed compared to the thermal performance of a natural convection heat sink with static fins under a fixed heat sink geometry condition. The thermal performance of the heat sink changes as the vibration amplitude of the fins or the vibration frequency of the fins changes. Particularly, if the vibration frequency of the fins matches up to the natural frequency of the fins, the vibration amplitude is significantly increased by resonance and the thermal performance also increases. The natural frequency of the fins changes with the heat sink temperature because the geometry of the fins changes and the properties of the fins change due to the temperature change.

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