scholarly journals Investigating effects of ball size on the performance of gas lift valve for both modified and optimized seats

2018 ◽  
Vol 73 ◽  
pp. 15
Author(s):  
Ehsanul Kabir ◽  
Hossein Emadi ◽  
Fathi Elldakli ◽  
Matt Young
Keyword(s):  
Dynamic Testing ◽  
Theoretical Calculations ◽  
Flow Coefficient ◽  
Experimental Program ◽  
Opening Pressure ◽  
Ball Size ◽  
Static Testing ◽  
Ball Diameter ◽  
Sharp Edges ◽  
Gas Lift

The seat and the ball are the only two components of a Gas Lift Valve (GLV) that can be switched out to meet changing gas throughput requirements. For this reason, individual pairings of balls and seats must be designed to meet the particular requirements of specific situations. While conventional GLV seats have sharp edges, a modified seat design with partially beveled edges has been shown to improve gas throughput. This design was then tested using benchmark valve and was optimized by beveling the entire port of the seat. These experiments were conducted using a ball diameter that was 0.0016 m larger than the diameter of the port top, although the effects of even larger ball sizes have also been studied using benchmark valves with conventional seats. Researchers have yet to explore the effects of ball diameters smaller than the Port Top Diameter (PTD) and larger than the Port Bottom Diameter (PBD) for modified and optimized seat designs. In this paper, the effects of smaller ball size on the GLV gas throughput have been analyzed using both modified and optimized seat designs and actual GLV. The ball was 0.0016 m smaller than the PTD of the seats. Geometric models have been deduced to calculate the generated upstream area (frustum area) open to flow. This frustum area is a function of stem travel, and the dimensions of the seat and ball. Theoretical calculations have been compared with results obtained through robust experimental methods. The entire experimental program was divided into four individual experiments. The static testing was used to fix the dome pressure and the opening pressure. The hysteresis effect associated with the bellows assembly was minimized using the aging procedure. Probe tester was used to measure the stem travel. Finally, the gas throughput of the GLV was measured using dynamic testing. The smaller ball sizes were found to significantly improve the gas throughput of actual GLV. This improvement was as high as 179% for large PBD seats. However, the frustum area practically decreased for these cases. This result suggests that the flow coefficient has more effect on GLV gas throughput compared to frustum area.

scholarly journals Influence of Frequency on the Resolution of Magnetostrictive Bio-Inspired Whisker Sensors

2018 ◽  
Vol 2018 ◽  
pp. 1-7
Author(s):  
Ran Zhao ◽  
Bo-wen Wang ◽  
Quan-guo Lu ◽  
Jian-wu Yan ◽  
Xiao-cui Yuan
Keyword(s):  
Vibration Frequency ◽  
Dynamic Testing ◽  
Theoretical Calculations ◽  
Beam Theory ◽  
Experimental System ◽  
Flow Sensors ◽  
Maximum Resolution ◽  
Sensing Model ◽  
Euler Bernoulli Beam ◽  
Good Agreement

Magnetostrictive biomimetic whiskers have been used as tactile and flow sensors. Compared to other types of whiskers, such whiskers have the advantage of being able to perform static and dynamic measurements. For dynamic measurement, the whisker’s resolution changes with varying vibration frequency; however, the mechanism for this influence has not been studied yet. Thus, the aim of this study is to investigate the resolution–frequency correlation. First, the structure and operation principle of the whisker were analyzed. Then, the Euler–Bernoulli beam theory was employed to establish the sensing model of the magnetostrictive whisker. Finally, the mapping relationship between sensor resolution and frequency was obtained. The eigenfrequency analysis was implemented by FEM to obtain the frequency response of the whisker. A vibration experimental system was built for dynamic testing. The experimental results were in good agreement with the theoretical calculations. Furthermore, it was noted that the resolution was positively correlated with frequency, and the maximum resolution was attained at the natural frequency (two peak values appeared at the first-order and second-order eigenfrequencies). Our research reveals the manner in which a whisker sensor’s resolution is affected by the vibration frequency. The theoretical model can be used to predict the resolution of magnetostrictive whisker sensors.

Effect of pre-drilling, loading rate and temperature variation on the behavior of railroad spikes used for high-density-polyethylene crossties

2016 ◽  
Vol 231 (1) ◽  
pp. 44-56 ◽  
Author(s):  
Ibrahim Lotfy ◽  
Maen Farhat ◽  
Mohsen A Issa
Keyword(s):  
Finite Element ◽  
High Density Polyethylene ◽  
High Density ◽  
Environmental Benefits ◽  
Experimental Program ◽  
Great Promise ◽  
Static Testing ◽  
Plastic Composite ◽  
Track System ◽  
The Usa

Railroad spikes represent a vital component of the rail track system, as they fasten the rail to the supporting crossties. Thus, it is important to understand its behavior and effect on the fastening assembly to mitigate any local failure, which, in turn, could lead to system deterioration or damage. Currently, alternative solutions to the traditional hardwood timber crossties are increasing being adopted by the railroad industry in the USA, with recycled plastic composite crossties being among the available alternatives. Their sustainably, environmental benefits, durability and ease of installation render them an attractive and competitive solution. Several research programs have studied this material and its fastening system in the past; however, additional research is required to fully understand the behavior of these materials and their interactions with the fastening system components. This paper presents an investigation that aims to understand and assess the performance of typical railroad spikes used for recycled high-density-polyethylene crossties. The study encompassed a comprehensive experimental investigation and analytical finite element modeling. The testing program evaluated railroad spikes using static testing methods recommended by the American Railway Engineering and Maintenance-of-Way Association (AREMA) manual. These tests addressed the rail spike pullout and lateral restraint for both screw and cut spikes. Finite element models were constructed and calibrated using the data obtained from the experimental program in order to extrapolate on the experimental results and predict the behavior of full-scale systems beyond the scale of the laboratory. The results observed in this study showed great promise, surpassing all the AREMA recommendations, which highlights the potential of these materials if properly optimized and engineered. Screw spikes exhibited a very good performance, surpassing the minimum recommendations by a significant margin (up to more than 200%) and are thus are highly recommended for future implementation.

Study on the Influence of Precise Ball Size for Mineral Indexes

2011 ◽  
Vol 402 ◽  
pp. 523-525
Author(s):  
Gui Ming Shi ◽  
Zheng Fei Li
Keyword(s):  
Economic Effects ◽  
Theoretical Formula ◽  
Ball Size ◽  
Experimental Part ◽  
Grinding Media ◽  
Experiment Method ◽  
Ball Diameter ◽  
Concentrate Grade ◽  
Steel Balls

This paper describes the experimental part of how to decide the optimizing size and ratio of grinding media with semi-theoretical formula of ball diameter and experiment method. The method can significantly increase the recovery and concentrate grade of tin, significantly decrease the steel balls consumption and attain better economic effects.

scholarly journals NUMERICAL AND EXPERIMENTAL RESEARCH OF YIELDING SUPPORTS IN DYNAMIC LOADING

2018 ◽  
pp. 103-110
Author(s):  
Z. R. Galyautdinov ◽  
D. R. Galyautdinov ◽  
M. V. Gandziy
Keyword(s):  
Dynamic Loading ◽  
Theoretical Calculations ◽  
Civil Defense ◽  
Finite Element Program ◽  
Static Testing ◽  
Industrial Enterprises ◽  
Element Program ◽  
Ring Section ◽  
Protective Structures ◽  
Yielding Support

Dynamic impacts of emergency nature occur in industrial enterprises and protective structures of civil defense. An effective way to reduce the dynamic impact is the use of yielding supports in the form of annular tubes. To assess the effect of deformation of yielding supports on reinforced concrete structures, it is necessary to determine the features of dynamic deformation of the crumpled inserts of the ring section. In theoretical calculations, characteristics obtained as a result of static testing yielding supports are currently used. Data on the dynamic characteristics of yielding supports are not available. This paper presents results of experimental and numerical studies on yielding supports under dynamic loading. Using the ANSYS finite element program, a numerical model is developed for the yielding support consistent with the obtained experimental data.

Cascade Research on a Small, Axial, High-Work, Cooled Turbine

1975 ◽  
Author(s):  
H. F. Due ◽  
A. E. Easterling ◽  
C. Rogo
Keyword(s):  
Flow Coefficient ◽  
Experimental Program ◽  
Inlet Temperature ◽  
Gas Generator ◽  
Cold Flow ◽  
Cooling Flow ◽  
Mechanical Constraints ◽  
Turboshaft Engine ◽  
Turbine Design ◽  
Design Power

This paper presents the results of an experimental cascade investigation of the aerodynamic performance of a 1.524-cm (0.6-in.) blade height, low aspect ratio, highly loaded, cooled turbine. The experimental program was performed with a cold flow annual sector cascade with various geometric and aerodynamic perturbations. The perturbation included nozzle endwall contour, inlet turbulence and velocity distortion, stator and rotor solidity, rotor loading and nozzle cooling flow and point of injection. The turbine design evolved through a parametric analysis considering a turboshaft engine configuration required to have a 750-hr life at design power output and satisfy realistic mechanical constraints. The gas generator turbine configuration selected for investigation was a single-stage turbine with a turbine inlet temperature of 1316 C (2400 F) and an actual work output of 418.68 kJ/kg, (180 Btu/lb). The baseline turbine was sized for a stage work coefficient of 5.0 at the hub radius and an average flow coefficient of 0.675 for a best mechanical-aerothermodynamic compromise to meet realistic engine constraints.

Seismic Design, Analysis and Testing of a Friction Steel Braced Frame System for Multi-Storey Buildings in Vancouver

2018 ◽  
Vol 763 ◽  
pp. 1077-1086 ◽  
Author(s):  
Lucia Tirca ◽  
Ovidiu Serban ◽  
Robert Tremblay ◽  
Yan Jiang ◽  
Liang Chen
Keyword(s):  
Energy Dissipation ◽  
Seismic Response ◽  
Dynamic Testing ◽  
Seismic Energy ◽  
Elastic Stiffness ◽  
Full Scale ◽  
Experimental Program ◽  
Test Program ◽  
Braced Frame ◽  
Seismic Displacement

This article describes the application of the Friction Braced Frames (FBF) system for 4-and 10-storey buildings located in Vancouver, BC, in Canada. The FBF is coupled with a secondary moment resisting frame that provides back-up elastic stiffness and re-centring capacity that contribute to reduce storey drifts and more evenly distribute seismic energy dissipation over the frame height. In this study, the energy dissipation components consist of Pall friction devices and the system was designed using a conventional force-based method. The moment frame was proportioned to remain essentially elastic under the design seismic displacements. The seismic response of the system is examined through nonlinear response history dynamic analysis. An exhaustive test program was developed to verify the capacity of the system to sustain the anticipated seismic demand. Full-scale testing was performed on brace sub-assemblages and individual brace specimens equipped with friction elements. The experimental program included full-scale dynamic testing under real-time seismic displacement histories as obtained from response history analysis. The numerical simulations and test program showed that the dual FBF system represents an effective system for enhanced seismic response of multi-storey building applications in high seismic regions.

Application of Accurate Ball-Load-Addition Method in Grinding Production of some Tailings

2014 ◽  
Vol 962-965 ◽  
pp. 771-774
Author(s):  
Kai Qi Huang ◽  
Ce Huan Xiao ◽  
Qi Ming Wu ◽  
Gui Chun He
Keyword(s):  
Steel Ball ◽  
Grinding Process ◽  
Filling Rate ◽  
Addition Method ◽  
Separation Index ◽  
Ball Size ◽  
Large Steel ◽  
Separation Degree ◽  
Ball Diameter

Grinding fitness caused by the failure of the steel ball filling rate, inappropriate steel ball matching, large steel ball size, etc. cannot meet follow-up flotation requirements. In order to optimize the ball grinding process, enhance the single separation degree of minerals and separation index, the steel ball diameter, steel ball matching and required additional balls of the mill are calculated with theoretical of ball radius formula and accurate filling ball method.

An Approximate Analysis and Prediction Method for Tip Clearance Loss in Axial Compressors

1994 ◽  
Vol 116 (4) ◽  
pp. 648-656 ◽  
Author(s):  
J. A. Storer ◽  
N. A. Cumpsty
Keyword(s):  
Simple Model ◽  
Tip Clearance ◽  
Flow Coefficient ◽  
Experimental Program ◽  
Leakage Flow ◽  
Tip Leakage Flow ◽  
Principal Mechanism ◽  
Axial Compressors ◽  
Tip Leakage ◽  
Clearance Flow

A simple model for loss created by the tip clearance flow in axial compressors is presented, based on an experimental program performed in conjunction with the Dawes three-dimensional Navier–Stokes calculation method. The principal mechanism of loss (entropy creation) caused by tip leakage flow has been established to be the mixing of flows of similar speeds but different direction. Calculations show that relative motion of the endwall relative to the tip has a small effect on clearance flow. The simple model correctly predicts the magnitude of tip clearance loss and the trend with changes of tip clearance for the cascade tested. For a given geometry the loss is almost exactly proportional to the ratio of tip clearance to blade span; the loss directly associated with the clearance is smaller than often assumed. The simple model for tip clearance loss has been expressed in terms of conventional nondimensional design variables (for example: solidity, aspect ratio, flow coefficient, loading coefficient) and from these the contribution to the overall loss of efficiency caused by tip leakage flow is conveniently represented. The trends are illustrated for a number of possible compressor design choices. Blade row loss increases more slowly than blade loading (for example, diffusion factor). As a result the decrement in stage efficiency associated with clearance flow decreases as the stage loading is raised in the practical range of flow and loading coefficients.

Low Emissions Combustion for the Regenerative Gas Turbine: Part 2—Experimental Techniques, Results, and Assessment

1974 ◽  
Vol 96 (1) ◽  
pp. 49-55 ◽  
Author(s):  
N. A. Azelborn ◽  
W. R. Wade ◽  
J. R. Secord ◽  
A. F. McLean
Keyword(s):  
Steady State ◽  
Gas Turbine ◽  
Theoretical Calculations ◽  
Experimental Program ◽  
Light Duty ◽  
Wide Range ◽  
Homogeneous Combustion ◽  
Model Year ◽  
Light Duty Vehicles ◽  
Geometry Test

This second part, of a two part paper, describes an experimental program to demonstrate the low emissions turbine combustor concept developed in Part 1. The paper discusses the combustor test rigs and instrumentation used as well as the experimental combustor hardware. A summary of the lean homogeneous combustion concept is presented along with a brief discussion of the requirement for variable combustor geometry. Test data are presented comparing the emissions from the experimental combustor with those from a conventional can-type combustor. These results show that, over a wide range of engine conditions, the steady-state emissions of NOx, CO, and UHC are below the numerical levels specified in the Federal standards applicable to 1976 and subsequent model year light duty vehicles. The results are related to theoretical calculations and an assessment of progress and remaining problems is made.

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