scholarly journals IMPROVEMENT OF TOTAL EFFICIENCY OF HYDROSTATIC TRANSMISSION BY USING OPTIMIZED CONTROL

2008 ◽  
Vol 2008 (7-2) ◽  
pp. 271-276 ◽  
Author(s):  
Mika IJAS ◽  
Esa MÄKINEN
Keyword(s):  
Total Efficiency ◽  
Hydrostatic Transmission

Outlet Surface Area Influence in Spiral Casing Design on Centrifugal Fan Performance

2020 ◽  
Vol 5 (1) ◽  
pp. 37-41
Author(s):  
Ardit Gjeta ◽  
Lorenc Malka
Keyword(s):  
Surface Area ◽  
Static Pressure ◽  
Total Efficiency ◽  
Centrifugal Fan ◽  
Recovery Coefficient ◽  
Fan Performance ◽  
Parameter Variations ◽  
Set Up ◽  
Spiral Casing ◽  
Pressure Recovery Coefficient

In this paper, the effect of the outlet surface area of the spiral casing on the performance of a centrifugal fan was investigated using open source CFD software OpenFOAM [1]. An automized loop with RANS and data post-processing is set up using Matlab, for allowing a large number of parameter variations. The effect was analyzed as a function of total pressure loss and static pressure recovery coefficient and on total efficiency as well.

On the application of the system of machines modular block type in the advanced technology logging activities

2016 ◽  
Author(s):  
С.А. Демидов
Keyword(s):  
Advanced Technology ◽  
Modular System ◽  
Process Equipment ◽  
Block Type ◽  
Work Efficiency ◽  
Operating Characteristics ◽  
Promising Direction ◽  
Hydrostatic Transmission ◽  
Machine Module

Рассматриваются возможности применения системы машин модульно-блочного типа в перспективных технологиях лесосечных работ, а также проблемы машинного парка лесозаготовительных предприятий России. Цель исследования - изучение структуры и особенностей эксплуатации системы лесных машин модульно блочного типа в современных условиях лесозаготовок с перспективой применения на ближайшее будущее. Для улучшения технологии проведения лесосечных работ и повышения экономической эффективности лесопромышленного комплекса предлагается провести ряд важных технических и технологических изменений. Одним из решений проблемы по улучшению эффективности работы является разработка и внедрение комплекса лесных машин, основанного на принципе эксплуатационной модульности. Это будет гарантировать технологическую гибкость производства, предоставит высокую производительность и обеспечит совместимость с окружающей средой. Приведен принцип устройства машин модульно-блочного типа с разделением функций между транспортными и технологическими модулями. Представлены графически классификация модулей по их назначению и концепция компоновки системы машин модульно-блочного типа, а также главный модуль (энергетический) и несколько технологических модулей, способных выполнять различные технологические операции в зависимости от условий и технологии производства. Как показал анализ рынка, наиболее перспективным направлением по улучшению механизации лесного парка машин является создание комплекса модульно-блочных машин на базе колесного трактора, оснащенных гидрообъемными передачами. Это делает конструкцию машины более гибкой и мобильной. Принцип формирования и работы модульной системы машин с многофункциональным технологическим оборудованием рассматривается в качестве перспективного направления по улучшению лесозаготовительного процесса. The article deals with the prospects for the use of machines modular block type in the advanced technology logging activities, as well as the machinery problems of logging enterprises in Russia. The research objective. The study of the structure and operating characteristics of a system of forest modular block type machines in current conditions with the prospect of their application in the nearest future. It is necessary that a number of important technical and technological changes should be made to improve the technology of logging operations and increase the economic efficiency of timber industry complex. One of the solutions to improve work efficiency is the development and introduction of forest machines based on the principle of operational modularity. It will ensure the flexibility of the production process, provide high work efficiency and, what counts, will be environmentally friendly. The article gives the description of the principle of the machine module block type, as well as the functions and how they are divided between the two modules. There are two pictures in the article. The first picture gives the classification of modules according to their application. The second picture shows the principle of arrangement of modular machine-block type. Both the main energetic module and some technological modules capable of performing processing steps depending on the conditions and production technology are presented. According to the market analysis that shows that the most promising direction to improve the mechanization of forest machinery is to create a complex modular block machines on the base of a wheeled tractor equipped with hydrostatic transmission. It will make the machine design more flexible and mobile. The principle of formation and operation of the modular system with multi-function machines process equipment is considered as a promising direction for improvement of the process of logging.

Field testing CFD-based predictions of storage chamber gross solids separation efficiency

1999 ◽  
Vol 39 (9) ◽  
pp. 161-168 ◽  
Author(s):  
Virginia R. Stovin ◽  
Adrian J. Saul ◽  
Andrew Drinkwater ◽  
Ian Clifforde
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Settling Velocity ◽  
Separation Efficiency ◽  
Flow Patterns ◽  
Total Efficiency ◽  
Separation Performance ◽  
Storage Chamber ◽  
Solids Separation ◽  
Simulated Flow

The use of computational fluid dynamics-based techniques for predicting the gross solids and finely suspended solids separation performance of structures within urban drainage systems is becoming well established. This paper compares the result of simulated flow patterns and gross solids separation predictions with field measurements made in a full size storage chamber. The gross solids retention efficiency was measured for six different storage chambers in the field and simulations of these chambers were undertaken using the Fluent computational fluid dynamics software. Differences between the observed and simulated flow patterns are discussed. The simulated flow fields were used to estimate chamber efficiency using particle tracking. Efficiency results are presented as efficiency cusps, with efficiency plotted as a function of settling velocity. The cusp represents a range of efficiency values, and approaches to the estimation of an overall efficiency value from these cusps are briefly discussed. Estimates of total efficiency based on the observed settling velocity distribution differed from the measured values by an average of ±17%. However, estimates of steady flow efficiency were consistently higher than the observed values. The simulated efficiencies agreed with the field observations in identifying the most efficient configuration.

scholarly journals Donut-Shaped mmWave Printed Antenna Array for 5G Technology

Electronics ◽  
2021 ◽  
Vol 10 (12) ◽  
pp. 1415
Author(s):  
Mian Muhammad Kamal ◽  
Shouyi Yang ◽  
Saad Hassan Kiani ◽  
Muhammad Rizwan Anjum ◽  
Mohammad Alibakhshikenari ◽  
...  
Keyword(s):  
Antenna Array ◽  
Ground Plane ◽  
Single Element ◽  
Total Efficiency ◽  
Printed Antenna ◽  
Central Frequency ◽  
Ring Shape ◽  
Dual Beam ◽  
High Bandwidth ◽  
Slotted Antenna

This article presents compact and novel shape ring-slotted antenna array operating at mmWave band on central frequency of 28 GHz. The proposed structure designed at 0.256 mm thin Roggers 5880 is composed of a ring shape patch with a square slot etched at the top mid-section of partial ground plane. Through optimizing the ring and square slot parameters, a high bandwidth of 8 GHz is achieved, ranging from 26 to 32 GHz, with a simulated gain of 3.95 dBi and total efficiency of 96% for a single element. The proposed structure is further transformed in a 4-element linear array manner. With compact dimensions of 20 mm × 22 mm for array, the proposed antenna delivers a high simulated gain of 10.7 dBi and is designed in such a way that it exhibits dual beam response over the entire band of interest and simulated results agree with fabricated prototype measurements.

Numerical simulation and experimental performance research of cylindrical vane pump

2021 ◽  
pp. 095440622110200
Author(s):  
Yiqi Cheng ◽  
Xinhua Wang ◽  
Waheed Ur Rehman ◽  
Tao Sun ◽  
Hasan Shahzad ◽  
...  
Keyword(s):  
Numerical Analysis ◽  
Rotational Velocity ◽  
Geometric Theory ◽  
Mechanical Efficiency ◽  
Operating Conditions ◽  
Experimental Results ◽  
Field Analysis ◽  
Total Efficiency ◽  
Three Dimensional Model ◽  
Vane Pump

This study presents a novel cylindrical vane pump based on the traditional working principle. The efficiency of the cylindrical vane pump was verified by experimental validation and numerical analysis. Numerical analysis, such as kinematics analysis, was performed in Pro/Mechanism and unsteady flow-field analysis was performed using ANSYS FLUENT. The stator surface equations were derived using the geometric theory of the applied spatial triangulation function. A three-dimensional model of the cylindrical vane pump was established with the help of MATLAB and Pro/E. The kinematic analysis helped in developing kinematic equations for cylindrical vane pumps and proved the effectiveness of the structural design. The maximum inaccuracy error of the computational fluid dynamics (CFD) model was 5.7% compared with the experimental results, and the CFD results show that the structure of the pump was reasonable. An experimental test bench was developed, and the results were in excellent agreement with the numerical results of CFD. The experimental results show that the cylindrical vane pump satisfied the three-element design of a positive-displacement pump and the trend of changes in efficiency was the same for all types of efficiency under different operating conditions. Furthermore, the volumetric efficiency presented a nonlinear positive correlation with increased rotational velocity, the mechanical efficiency showed a nonlinear negative correlation, and the total efficiency first increased and then decreased. When the rotational velocity was 1.33[Formula: see text] and the discharge pressure was 0.68[Formula: see text], the total efficiency reached its maximum value.

scholarly journals A Novel Hook-Shaped Antenna Operating at 28 GHz for Future 5G mmwave Applications

Electronics ◽  
2021 ◽  
Vol 10 (6) ◽  
pp. 673
Author(s):  
Mian Kamal ◽  
Shouyi Yang ◽  
Saad Kiani ◽  
Daniyal Sehrai ◽  
Mohammad Alibakhshikenari ◽  
...  
Keyword(s):  
Antenna Array ◽  
Communication Systems ◽  
Broad Band ◽  
High Gain ◽  
Single Element ◽  
Total Efficiency ◽  
Potential Candidate ◽  
Next Generation ◽  
Dual Beam ◽  
Element Array

To address atmospheric attenuation and path loss issues in the mmwave portion of the spectrum, high gain and narrow beam antenna systems are essential for the next generation communication networks. This paper presents a novel hook-shaped antenna array for 28 GHz 5G mmwave applications. The proposed antenna was fabricated on commercially available Rogers 5880 substrate with thickness of 0.508 mm and dimensions of 10 × 8 mm2. The proposed shape consists of a circle with an arc-shaped slot on top of it and T-shaped resonating lengths are introduced in order to attain broad band characteristics having gain of 3.59 dBi with radiation and total efficiency of 92% and 86% for single element. The proposed structure is transformed into a four-element array with total size of 26.9 × 18.5 mm2 in order to increase the gain up to 10.3 dBi at desired frequency of interest. The four-element array is designed such that it exhibits dual-beam response over the entire band of interest and the simulated results agree with fabricated prototype measurements. The proposed antenna array, because of its robustness, high gain, and dual-beam characteristics can be considered as a potential candidate for the next generation 5G communication systems.

Process Analysis for Achieving Highly Enhanced Total Efficiency on Multi-Stage Fuel Supplied SOFC System

2015 ◽  
Vol 68 (1) ◽  
pp. 3107-3113
Author(s):  
Y. Tachikawa ◽  
Y. Matsuzaki ◽  
T. Hatae ◽  
S. Taniguchi ◽  
K. Sasaki
Keyword(s):  
Process Analysis ◽  
Total Efficiency ◽  
Multi Stage
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