Numerical Study of the Efficiency of a Heating Cable in the Dewaxing of High-Rate Wells

2021 ◽  
Author(s):  
Nikita Kostarev ◽  
Natalia Trufanova
Keyword(s):  
Numerical Study ◽  
High Rate ◽  
Heating Cable

Controlling the Postbuckling Response of Cylindrical Shells Under Axial Compression for Applications in Smart Structures

2013 ◽  
Author(s):  
Rigoberto Burgueño ◽  
Nan Hu ◽  
Nizar Lajnef
Keyword(s):  
Energy Harvesting ◽  
Axial Compression ◽  
Frequency Tuning ◽  
Numerical Study ◽  
Limit State ◽  
Cylindrical Shells ◽  
High Rate ◽  
Postbuckling Behavior ◽  
Response Range ◽  
Ultimate Failure

Elastic instability, long considered mainly as a failure limit state or a safety guard against ultimate failure is gaining increased interest due to the development of active and controllable structures, and the growth in computational power. Mode jumping, or snap-through, during the postbuckling response leads to sudden and high-rate deformations due to generally smaller changes in the controlling load or displacement input to the system. A paradigm shift is thus emerging in using the unstable response range of slender structures for purposes that are rapidly increasing and diversifying, including applications such as energy harvesting, frequency tuning, sensing and actuation. This paper presents a finite element based numerical study on controlling the postbuckling behavior of fiber reinforced polymer cylindrical shells under axial compression. Considered variables in the numerical analyses include: the ply orientation and laminate stacking sequence; the material distribution on the shell surface (stiffness distribution); and the anisotropic coupling effects. Preliminary results suggest that the static and dynamic response of unstable mode branch switching during postbuckling can be fully characterized, and that their number and occurrence can be potentially tailored. Use of the observed behavior for energy harvesting and other sensing and actuation applications will be presented in future studies.

scholarly journals Experimental and Numerical Study of Concrete Targets under High Rate of Loading

2017 ◽  
Vol 173 ◽  
pp. 130-137 ◽  
Author(s):  
Abhishek Rajput ◽  
M.A. Iqbal ◽  
P. Bhargava
Keyword(s):  
Numerical Study ◽  
High Rate ◽  
Rate Of Loading

scholarly journals Numerical Study of Adsorption Enhancement by Nanoparticles Scale Inhibitor

2015 ◽  
Vol 1119 ◽  
pp. 43-48 ◽  
Author(s):  
John Kia Yu Teck ◽  
Radhiyatul Hikmah binti Abu ◽  
Siti Ujila binti Masuri
Keyword(s):  
Concentration Distribution ◽  
Active Sites ◽  
Flow Model ◽  
Numerical Study ◽  
High Rate ◽  
Scale Inhibitor ◽  
Ansys Fluent ◽  
Column Wall ◽  
Computational Fluid Dynamics Cfd ◽  
Simulation Time

This paper describes the numerical investigation on the adsorption () of nanoparticles (NPs) scale inhibitor (SI) using Eulerian Computational Fluid Dynamics (CFD) solver ANSYS/FLUENT® based on a scaled down flow model. The simulation were done to investigate theof normal and nanoscaled Calcium-phosphonate. The phosphonate used was 1-hydroxyethylidene-1, 1-disphosphonic acid (HEDP) SI in order to determine the enhancement in adsorption achieved by the nanoscaled SI. This was done by looking at the change in concentration of the SI particles throughout the simulation time. It was found that the two sizes (normal and nanostructured) of the SI particles result in different change in concentration, hence indicates that the two yields different adsorption to the active sites. For the normal SI, the concentration distribution throughout the column remains almost the same as its initial concentration () of 2000 ppm except for very narrow regions in the vicinity of the wall boundaries. This suggests that the rate of process (of the SI onto the wall) is very slow. Consequently, it will take longer time for the SI to be adsorbed to the column wall, hence indicates that it is less efficient. Meanwhile, the nanoscaled Calcium-HEDP SI rapidly shows a significant change in concentration. At 200 s its concentration has distributed evenly in the range of 1960 ppm to 2000 ppm. This shows a really high rate. The results from this study indicates that the nanoscaled Calcium-HEDP SI has better which shows that it is more efficient than normal-scaled Calcium-HEDP SI.

scholarly journals A Study of Rotor Cavities and Heat Transfer in a Cooling Process in a Gas Tubine

1992 ◽  
Author(s):  
R. S. Amano ◽  
V. Pavelic
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Gas Flow ◽  
Numerical Study ◽  
Heat Transfer Process ◽  
High Rate ◽  
Turbulent Heat Transfer ◽  
Air Cooling ◽  
Turbulent Heat ◽  
Accurate Analysis

A high temperature flow through a gas-turbine produces a high rate of turbulent heat transfer between the fluid flow field and the turbine components. The heat transfer process through rotor disks causes thermal stress due to the thermal gradient as well as the centrifugal force causes mechanical stresses; thus an accurate analysis for the evaluation of thermal behavior is needed. This paper presents a numerical study of thermal flow analysis in a two-stage turbine in order to better understand the detailed flow and heat transfer mechanisms through the cavity and the rotating rotor-disks. The numerical computations were performed to predict thermal fields throughout the rotating disks. The method used in this paper is the ‘segregation’ method which requires a much smaller number of grids than actually employed in the computations. The results are presented for temperature distributions through the disk and the velocity fields which illustrate the interaction between the cooling air flow and gas flow created by the disk rotation. The temperature distribution in the disks shows a reasonable trend. The numerical method developed in this study shows that it can be easily adapted for similar computations for air cooling flow patterns through any rotating blade disks in a gas turbine.

A Study of Rotor Cavities and Heat Transfer in a Cooling Process in a Gas Turbine

1994 ◽  
Vol 116 (2) ◽  
pp. 333-338 ◽  
Author(s):  
R. S. Amano ◽  
K. D. Wang ◽  
V. Pavelic
Keyword(s):  
Heat Transfer ◽  
Gas Turbine ◽  
Gas Flow ◽  
Numerical Study ◽  
Heat Transfer Process ◽  
High Rate ◽  
Turbulent Heat Transfer ◽  
Air Cooling ◽  
Turbulent Heat ◽  
Accurate Analysis

A high-temperature flow through a gas turbine produces a high rate of turbulent heat transfer between the fluid flow field and the turbine components. The heat transfer process through rotor disks causes thermal stress due to the thermal gradient just as the centrifugal force causes mechanical stresses; thus an accurate analysis for the evaluation of thermal behavior is needed. This paper presents a numerical study of thermal flow analysis in a two-stage turbine in order to understand better the detailed flow and heat transfer mechanisms through the cavity and the rotating rotor-disks. The numerical computations were performed to predict thermal fields throughout the rotating disks. The method used in this paper is the “segregation” method, which requires a much smaller number of grids than actually employed in the computations. The results are presented for temperature distributions through the disk and the velocity fields, which illustrate the interaction between the cooling air flow and gas flow created by the disk rotation. The temperature distribution in the disks shows a reasonable trend. The numerical method developed in this study shows that it can be easily adapted for similar computations for air cooling flow patterns through any rotating blade disks in a gas turbine.

scholarly journals Static test of a variable stiffness thermoplastic composite wingbox under shear, bending and torsion

2020 ◽  
Vol 124 (1275) ◽  
pp. 635-666
Author(s):  
G. Zucco ◽  
V. Oliveri ◽  
M. Rouhi ◽  
R. Telford ◽  
G. Clancy ◽  
...  
Keyword(s):  
Finite Element ◽  
Composite Structures ◽  
Numerical Study ◽  
Variable Stiffness ◽  
Buckling Load ◽  
Thermoplastic Composite ◽  
High Rate ◽  
Thermoplastic Composites ◽  
Test Rig ◽  
Shear Bending

AbstractAutomated manufacturing of thermoplastic composites has found increased interest in aerospace applications over the past three decades because of its great potential in low-cost, high rate, repeatable production of high performance composite structures. Experimental validation is a key element in the development of structures made using this emerging technology. In this work, a $750\times640\times240$ mm variable-stiffness unitised integrated-stiffener out-of-autoclave thermoplastic composite wingbox is tested for a combined shear-bending-torsion induced buckling load. The wingbox is manufactured by in-situ consolidation using a laser-assisted automated tape placement technique. It is made and tested as a demonstrator section located at 85% of the wing semi-span of a B-737/A320 sized aircraft. A bespoke in-house test rig and two aluminium dummy wingboxes are also designed and manufactured for testing the wingbox assembly which spans more than 3m. Prior to testing, the wingbox assembly and the test rig were analysed using a high fidelity finite element method to minimise the failure risk due to the applied load case. The experimental test results of the wingbox are also compared with the predictions made by a numerical study performed by nonlinear finite element analysis showing less than 5% difference in load-displacement behaviour and buckling load and full agreement in predicting the buckling mode shape.

scholarly journals Numerical Study of Drying of Suspension Droplets in High Rate Evaporation Processes

2020 ◽  
Author(s):  
Seyyed Morteza Javid ◽  
Christian Moreau ◽  
Javad Mostaghimi
Keyword(s):  
Numerical Study ◽  
High Rate

Structure of Palladium Single-Crystal Films Prepared by Flash Evaporation onto (001) NaCl Substrates

1970 ◽  
Vol 28 ◽  
pp. 456-457
Author(s):  
L. E. Murr ◽  
G. Wong
Keyword(s):  
Single Crystal ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
High Rate ◽  
Flash Evaporation ◽  
Optimum Load ◽  
Single Crystal Films ◽  
Crystal Films ◽  
A Current

Palladium single-crystal films have been prepared by Matthews in ultra-high vacuum by evaporation onto (001) NaCl substrates cleaved in-situ, and maintained at ∼ 350° C. Murr has also produced large-grained and single-crystal Pd films by high-rate evaporation onto (001) NaCl air-cleaved substrates at 350°C. In the present work, very large (∼ 3cm2), continuous single-crystal films of Pd have been prepared by flash evaporation onto air-cleaved (001) NaCl substrates at temperatures at or below 250°C. Evaporation rates estimated to be ≧ 2000 Å/sec, were obtained by effectively short-circuiting 1 mil tungsten evaporation boats in a self-regulating system which maintained an optimum load current of approximately 90 amperes; corresponding to a current density through the boat of ∼ 4 × 104 amperes/cm2.

Rapid Freezing of Freeze-Etch Specimens

1980 ◽  
Vol 38 ◽  
pp. 752-755
Author(s):  
A. Elgsaeter ◽  
T. Espevik ◽  
G. Kopstad
Keyword(s):  
Low Temperature ◽  
Metal Surface ◽  
Relative Velocity ◽  
Thermal Contact ◽  
High Rate ◽  
Rapid Freezing ◽  
Temperature Decrease ◽  
Freeze Etching

The importance of a high rate of temperature decrease (“rapid freezing”) when freezing specimens for freeze-etching has long been recognized1. The two basic methods for achieving rapid freezing are: 1) dropping the specimen onto a metal surface at low temperature, 2) bringing the specimen instantaneously into thermal contact with a liquid at low temperature and subsequently maintaining a high relative velocity between the liquid and the specimen. Over the last couple of years the first method has received strong renewed interest, particularily as the result of a series of important studies by Heuser and coworkers 2,3. In this paper we will compare these two freezing methods theoretically and experimentally.

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