scholarly journals EXPERIMENTAL INVESTIGATIONS ON THE SURFACE APPLICATION OF SUPERPHOSPHATE BY THE FERTILISER SPREADING TOOL WITH INCLINED AXIS

2021 ◽  
pp. 307-316
Author(s):  
Volodymyr Bulgakov ◽  
Oleg Adamchuk ◽  
Semjons Ivanovs ◽  
Juri Olt
Keyword(s):  
Horizontal Plane ◽  
Rotation Frequency ◽  
Experimental Investigations ◽  
Experimental Setup ◽  
Surface Application ◽  
Axis Of Rotation ◽  
Disc Rotation

One of the possible ways to significantly increase the spreading distance of fertilisers (and, accordingly, efficiency) by the fertiliser spreading tools may be creation of a structure with an inclined axis of rotation. For experimental investigations an experimental setup was developed and a solid mineral superphosphate granular fertiliser was used as a material. Increasing the angle of inclination of the disc of the fertiliser sowing tool with an inclined axis in a horizontal plane from 0 to 30º at a disc rotation frequency of 1000 min-1 leads to an increase in the effective sieving distance of granulated superphosphate by 34.9. It has been established that the best indices of mineral fertilisation both in terms of the operating width and the irregularity of the fertiliser introduction are provided at the angles of inclination of the disc of the new fertiliser distributing tool in a horizontal plane within 25-30º.

scholarly journals A Critical Review of Experimental Investigations about Convective Heat Transfer Characteristics of Nanofluids under Turbulent and Laminar Regimes with a Focus on the Experimental Setup

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 6004
Author(s):  
Gianpiero Colangelo ◽  
Noemi Francesca Diamante ◽  
Marco Milanese ◽  
Giuseppe Starace ◽  
Arturo de Risi
Keyword(s):  
Heat Transfer ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Convective Heat Transfer ◽  
Convective Heat ◽  
Convective Heat Transfer Coefficient ◽  
Research Field ◽  
Experimental Investigations ◽  
Experimental Setup ◽  
Increase Energy Efficiency

In this study, several experimental investigations on the effects of nanofluids on the convective heat transfer coefficient in laminar and turbulent conditions were analyzed. The aim of this work is to provide an overview of the thermal performance achieved with the use of nanofluids in various experimental systems. This review covers both forced and natural convection phenomena, with a focus on the different experimental setups used to carry out the experimental campaigns. When possible, a comparison was performed between different experimental campaigns to provide an analysis of the possible common points and differences. A significant increase in the convective heat transfer coefficient was found by using nanofluids instead of traditional heat transfer fluids, in general, even with big data dispersion from one case to another that depended on boundary conditions and the particular experimental setup. In particular, a general trend shows that once a critic value of the Reynolds number or nanoparticle concentrations is reached, the heat transfer performance of the nanofluid decreases or has no appreciable improvement. As a research field still under development, nanofluids are expected to achieve even higher performance and their use will be crucial in many industrial and civil sectors to increase energy efficiency and, thus, mitigate the environmental impact.

Sensorimotor aspects of high-speed artificial gravity: II. The effect of head position on illusory self motion

2003 ◽  
Vol 12 (5-6) ◽  
pp. 283-289
Author(s):  
Fred W. Mast ◽  
Nathaniel J. Newby ◽  
Laurence R. Young
Keyword(s):  
Healthy Subjects ◽  
Horizontal Plane ◽  
High Speed ◽  
Semicircular Canals ◽  
Vertical Axis ◽  
Head Position ◽  
Artificial Gravity ◽  
Axis Of Rotation ◽  
Self Motion

The effects of cross-coupled stimuli on the semicircular canals are shown to be influenced by the position of the subject's head with respect to gravity and the axis of rotation, but not by the subject's head position relative to the trunk. Seventeen healthy subjects made head yaw movements out of the horizontal plane while lying on a horizontal platform (MIT short radius centrifuge) rotating at 23 rpm about an earth-vertical axis. The subjects reported the magnitude and duration of the illusory pitch or roll sensations elicited by the cross-coupled rotational stimuli acting on the semicircular canals. The results suggest an influence of head position relative to gravity. The magnitude estimation is higher and the sensation decays more slowly when the head's final position is toward nose-up (gravity in the subject's head x-z-plane) compared to when the head is turned toward the side (gravity in the subject's head y-z-plane). The results are discussed with respect to artificial gravity in space and the possible role of pre-adaptation to cross-coupled angular accelerations on earth.

Fatigue strength of disk cutting tool of robotic equipment

2020 ◽  
pp. 58-62
Author(s):  
A.YU Karpachev ◽  
A.S. Voyakin
Keyword(s):  
Fatigue Strength ◽  
Cutting Tool ◽  
Rotation Frequency ◽  
Inertial Forces ◽  
Disk Model ◽  
Spatial Rotation ◽  
Circular Saw ◽  
Disc Rotation ◽  
Spherical Motion

The spatial rotation of the robotic unit cutting disk model is considered. The connection between the stresses in the disk and the kinematics of spherical motion is established. A criterion for the fatigue strength of a disk of robotic equipment is proposed. Keywords circular saw, disc, rotation frequency, inertial forces. [email protected]

Experimental Investigations of Debris Dynamics over a Horizontal Plane

2017 ◽  
Vol 143 (3) ◽  
pp. 04016022 ◽  
Author(s):  
Ioan Nistor ◽  
Nils Goseberg ◽  
Jacob Stolle ◽  
Takahito Mikami ◽  
Tomoya Shibayama ◽  
...  
Keyword(s):  
Horizontal Plane ◽  
Experimental Investigations

Unsteady Steam Turbine Optimization Using High Fidelity CFD

2020 ◽  
Author(s):  
Vahid Iranidokht ◽  
Ilias Papagiannis ◽  
Anestis Kalfas ◽  
Reza Abhari ◽  
Shigeki Senoo ◽  
...  
Keyword(s):  
Steam Turbine ◽  
Computational Cost ◽  
Flow Distribution ◽  
Fast Response ◽  
Test Facility ◽  
Experimental Investigations ◽  
Experimental Setup ◽  
Efficiency Gain ◽  
Flow Angle ◽  
Computational Optimization

Abstract This paper presents the computational methodology, and experimental investigations accomplished to enhance the efficiency of a turbine stage by applying non-axisymmetric profiling on the rotor hub wall. The experimental setup was a two-stage axial turbine, which was tested at “LISA” test facility at ETH Zurich. The 1st stage was considered to create the flow history for the 2nd stage, which was the target of the optimization. The hub cavity of the 2nd stage was designed with large dimensions as a requirement of a steam turbine. The goal was to optimize the interaction of the cavity leakage flow with the rotor passage flow to reduce the losses and increase efficiency. The computational optimization was completed using a Genetic Algorithm coupled with an Artificial Neural Network on the 2nd stage of the test turbine. Unsteady time-accurate simulations were performed, using in-house developed “MULTI3” solver. Besides implementing all geometrical details (such as hub and tip cavities and fully 3D blade geometries) from the experimental setup into the computational model, it was learned that the unsteady upstream effect could not be neglected. A novel approach was introduced by using unsteady inlet boundary conditions to consider the multistage effect while reducing the computational cost to half. The importance of this implementation was tested by performing a steady simulation on the optimized geometry. The predicted efficiency gain from steady simulations was 4.5 times smaller (and negligible) compared to the unsteady approach. Excluding the cavity geometry was also assessed in a different simulation setup showing 3.9% over-prediction in the absolute efficiency value. Comprehensive steady and unsteady measurements were performed utilizing pneumatic, Fast Response Aerodynamic (FRAP), and Fast Response Entropy (FENT) probes, on the baseline and profiled test cases. The end-wall profiling was found to be successful in weakening the strength of the hub passage vortex by a 19% reduction in the under-over turning. As a result, the blockage was reduced near the hub region leading to more uniform mass flow distribution along the span. The flow angle deviations at the higher span position were also corrected due to better control of the flow angles. Furthermore, the improvements were confirmed by reductions in entropy, Secondary Kinetic Energy, and pressure unsteadiness. The accurate computational implementations led to an excellent agreement between the predicted and measured efficiency gain.

Experimental Investigations on the Thermal Conductivity of Silica Aerogels by a Guarded Thin-Film-Heater Method

2009 ◽  
Vol 131 (7) ◽  
Author(s):  
Sandra Spagnol ◽  
Bérangère Lartigue ◽  
Alain Trombe ◽  
Florence Despetis
Keyword(s):  
Thin Film ◽  
Experimental Data ◽  
Thermal Conductivity ◽  
Direct Measurement ◽  
Silica Aerogels ◽  
Experimental Investigations ◽  
Experimental Setup ◽  
Insulating Materials ◽  
Grain Sizes ◽  
Major Interest

A thin-film-heater method is setup to measure the thermal conductivity of super insulating materials such as silica aerogels. The experimental setup is purposely designed for insulating materials and allows direct measurement of the thermal conductivity. Few experimental data are available in the literature concerning thermal conductivity of aerogels even though these materials are of major interest in thermal insulation. More data are necessary in order to understand thermal transport and to validate existing models. Monolithic and granular silica aerogels are investigated. Our experimental technique enables to quantify the influence of important parameters, such as air pressure and distribution of grain sizes, on the insulating performance of this material.

Investigation of Frictional Effects on Buckling Behavior of Drill String

2013 ◽  
Author(s):  
Jamil Abdo ◽  
Hamed Al-Sharji ◽  
Danish Haneef ◽  
Khalid Alzebdeh
Keyword(s):  
Friction Coefficient ◽  
Friction Factor ◽  
Drilling Fluid ◽  
Drill String ◽  
Experimental Investigations ◽  
Experimental Setup ◽  
Buckling Behavior ◽  
Force Transfer ◽  
Fluid Rheology ◽  
Frictional Effects

The in-house developed experimental setup that imitates the wellbore being drilled in presence of surrounding drilling fluid is utilized to investigate the buckling phenomena of drill string. The paper also presents experimental investigations on the effect of changing the friction coefficient on the buckling lock-up situations of drill string. Results reveal that axial transferred loads decrease with the increase of friction coefficient. The results, highlights the significance of changing the drilling fluid rheology, mainly the friction factor, to reduce the friction between the wellbore and the tubing, and thus improve axial force transfer which is mainly responsible for initiation of buckling and limited reach of drilling operation. Drilling fluid with lower friction factor significantly reduces the friction between the tubing and the wellbore. The tube takes the same shape with the change of COF at the same load.

Unsteady Steam turbine optimization using high fidelity CFD

2021 ◽  
pp. 1-56
Author(s):  
Vahid Iranidokht ◽  
Ilias Papagiannis ◽  
Anestis I. Kalfas ◽  
Reza S. Abhari ◽  
Shigeki Senoo ◽  
...  
Keyword(s):  
Computational Cost ◽  
Flow Distribution ◽  
Fast Response ◽  
Test Facility ◽  
Experimental Investigations ◽  
Experimental Setup ◽  
Efficiency Gain ◽  
Computational Optimization ◽  
Novel Approach ◽  
Measured Efficiency

Abstract This paper presents the computational methodology, and experimental investigations accomplished to enhance the efficiency of a turbine stage by applying non-axisymmetric profiling on the rotor hub wall. The experimental setup was a two-stage axial turbine, which was tested at “LISA” test facility at ETH Zurich. The goal was to optimize the interaction of the cavity leakage flow with the rotor passage flow to increase efficiency. The computational optimization was completed using a Genetic Algorithm coupled with an Artificial Neural Network. Unsteady time-accurate simulations were performed, using in-house developed “MULTI3” solver. Besides implementing all geometrical details from the experimental setup into the computational model, it was learned that the unsteady upstream effect could not be neglected. A novel approach was introduced by using unsteady inlet boundary conditions to consider the multistage effect while reducing the computational cost to half. Comprehensive steady and unsteady measurements were performed utilizing pneumatic, Fast Response Aerodynamic (FRAP), and Fast Response Entropy (FENT) probes, on the baseline and profiled test cases. The end-wall profiling was found to be successful in weakening the strength of the hub passage vortex by a 19% reduction in the under-over turning. As a result, the blockage was reduced near the hub region leading to more uniform mass flow distribution along the span. Furthermore, the improvements were confirmed by reductions in entropy, Secondary Kinetic Energy, and pressure unsteadiness. The accurate computational implementations led to an excellent agreement between the predicted and measured efficiency gain.

Model investigation of the performance of single anchors and groups of anchors

1994 ◽  
Vol 31 (2) ◽  
pp. 273-284 ◽  
Author(s):  
Ashraf Ghaly ◽  
Adel Hanna
Keyword(s):  
Failure Mechanism ◽  
Load Distribution ◽  
Dense Medium ◽  
Unit Weight ◽  
Experimental Investigations ◽  
Experimental Setup ◽  
Uplift Capacity ◽  
Sand Surface ◽  
Pullout Load ◽  
Upward Displacement

Experimental investigations on the performance of single and groups of vertical screw anchors installed in dense, medium, and loose sands are presented. An experimental setup was instrumented to allow the measurement of the total pullout load, upward displacement, sand surface deflection, and stress development in the sand layer during all phases of testing. A sand placing technique was developed and utilized over all the testing program to ensure reproducibility of the predetermined unit weight. Stresses measured within sand deposits indicated that the tested sands were overconsolidated due to the application of mechanical compaction. Special tests were conducted on colored–layered sand to define the nature of the failure mechanism. The results of these tests, together with the measurements of the deflection of the sand surface, were employed to establish the shape of the rupture surface which could be represented by a segment of a logarithmic spiral. Groups of three, four, six, and nine anchors were tested in this investigation. The effect of installation depth, spacing between anchors, and sand characteristics on the ultimate pullout load of the group was examined. The experimental setup was instrumented to allow the measurement, of the total pullout load of the group as well as that of individual anchors in the group. Load distribution among the anchors of a group is discussed in terms of anchor location and the applied load level. At failure, all anchors contribute almost equally to the uplift capacity. Group efficiencies were calculated and compared. An installation procedure was proposed to avoid differential upward displacement during the uplifting process and to provide uniform load distribution on the different anchors of the group. Key words : anchors, failure mechanism, group action, model tests, sand, uplift capacity.

scholarly journals Study of the continuous mode of mixing feed components in a mixing plant

2021 ◽  
Vol 1 (4) ◽  
pp. 71-76
Author(s):  
P.N. Solonshchikov ◽  
Keyword(s):  
Experimental Studies ◽  
Electric Energy ◽  
Animal Husbandry ◽  
Rotation Frequency ◽  
Electrical Energy ◽  
Experimental Setup ◽  
Liquid Feed ◽  
Complex Mechanization ◽  
Technological Institutes ◽  
Planning Methods

The article discusses the problem of developing means that can increase the efficiency of mecha-nization of the process of preparing liquid feed in animal husbandry. Design bureaus, research and technological institutes for mechanization and electrification of agriculture have developed new progressive technologies, as well as kits, units, machines and apparatus for animal husbandry and fodder production. On the basis of this technique, complex mechanization of farms is being intro-duced and livestock complexes with industrial production technology are being created. But recent-ly, the widespread use of domestic machines for the preparation of liquid feed mixtures has not been presented. Therefore, an experimental setup that combines three functions: a batcher, a pump and a mixer is proposed. It ultimately allows to obtain a mixture of good quality. The article pro-vides a program and research methodology for the setup. For this, a special test bench has been de-veloped. It makes possible to determine the parameters of the mixture quality and the specific con-sumption of electrical energy. As a search for the optimal combination of factors for the optimiza-tion criteria: the degree of homogeneity and the specific consumption of electrical energy, plan 32 was chosen. Experimental studies have shown the range of supply of the installation at different speeds of rotation of the impeller shaft. Mixing studies have confirmed the effectiveness of the de-sign of the plant and its components: dispenser, pump and mixer. With the help of experimental planning methods, the main factors influencing the mixing process are identified, and the optimal parameters of the mixture quality are determined. According to the studies of the continuous intro-duction of components in an experimental setup for the preparation of liquid feed mixtures, it was obtained that the optimal combinations of factors would be the water temperature t = 26 ... 38 oC and the rotation frequency n = 1500 ... 1650 min-1, while the degree of homogeneity reaches Θ = 94,6% and unit costs of electric energy Eel = 0.198 kWh / t.d. h.

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