Rotor Scale Model Tests for Power Conversion Unit of GT-MHR

2008 ◽  
Author(s):  
C. B. Baxi ◽  
N. G. Kodochigov ◽  
S. E. Belov ◽  
M. N. Borovkov
Keyword(s):  
Power Conversion ◽  
Model Tests ◽  
Suspension System ◽  
Full Scale ◽  
Magnetic Bearings ◽  
Scale Model ◽  
Small Scale ◽  
Conversion Unit ◽  
Electro Magnetic ◽  
Rotor Model

A power-generating unit with the high-temperature helium reactor (GT-MHR) has a turbomachine (TM) that is intended for both conversion of coolant thermal energy into electric power in the direct gas-turbine cycle, and provision of helium circulation in the primary circuit. The vertically oriented TM is placed in the central area of the power conversion unit (PCU). TM consists of a turbocompressor (TC) and a generator. Their rotors are joined with a diaphragm coupling and supported by electro-magnetic bearings (EMB). The complexity and novelty of the task of the full electromagnetic suspension system development requires thorough stepwise experimental work, from small-scale physical models to full-scale specimen. On this purpose, the following is planned within the framework of the GT-MHR Project: investigations of the “flexible” rotor small-scale mockup with electro-magnetic bearings (“Minimockup” test facility); tests of the radial EMB; tests of the position sensors; tests of the TM rotor scale model; tests of the TM catcher bearings (CB) friction pairs; tests of the CB mockups; tests of EMB and CB pilot samples and investigation of the full-scale electromagnetic suspension system as a part of full-scale turbocompressor tests. The rotor scale model (RSM) tests aim at investigation of dynamics of rotor supported by electromagnetic bearings to validate GT-MHR turbomachine serviceability. Like the full-scale turbomachine rotor, the RSM consist of two parts: the generator rotor model and the turbocompressor rotor model that are joined with a coupling. Both flexible and rigid coupling options are tested. Each rotor is supported by one axial and two radial EMBs. The rotor is arranged vertically. The RSM rotor length is 10.54 m, and mass is 1171 kg. The designs of physical model elements, namely of the turbine, compressors, generator and exciter, are simplified and performed with account of rigid characteristics, which are identical to those of the full-scale turbomachine elements.

Evaluation of a Small and Fast Planing Boat’s Seakeeping Performance at the Design Stage

2015 ◽  
Author(s):  
Dong Jin Kim ◽  
Sun Young Kim
Keyword(s):  
Model Tests ◽  
Full Scale ◽  
Scale Model ◽  
Design Stage ◽  
Small Scale ◽  
Irregular Wave ◽  
Seakeeping Performance ◽  
Head Waves ◽  
Scale Ratio ◽  
Free Running

Seakeeping performance of a planing boat should be sufficiently considered and evaluated at the design stage for its safe running in rough seas. Model tests in seakeeping model basins are often performed to predict the performance of full-scale planing boats. But, there are many limitations of tank size and wave maker capacity, in particular, for fast small planing boats due to small scale ratio and high Froude numbers of their scale models. In this research, scale model tests are tried in various test conditions, and results are summarized and analyzed to predict a 3 ton-class fast small planing boats designed. In a long and narrow tank, towing tests for a bare hull model are performed with regular head waves and long crested irregular head waves. Motion RAOs are derived from irregular wave tests, and they are in good agreements with RAOs in regular waves. Next, model ships with one water-jet propulsion system are built, and free running model tests are performed in ocean basins. Wave conditions such as significant heights, modal periods, and directions are varied for the free running tests. Motion RMS values, and RAOs are obtained through statistical approaches. They are compared with the results in captive tests for the bare hull model, and are used to predict the full-scale boat performances.

Rotor scale model tests for power conversion unit of GT-MHR

2012 ◽  
Vol 251 ◽  
pp. 344-348 ◽  
Author(s):  
C.B. Baxi ◽  
A. Telengator ◽  
J. Razvi
Keyword(s):  
Power Conversion ◽  
Model Tests ◽  
Scale Model ◽  
Conversion Unit

Drilling Riser VIV Tests With Prototype Reynolds Numbers

2013 ◽  
Author(s):  
Halvor Lie ◽  
Henning Braaten ◽  
Jamison Szwalek ◽  
Massimiliano Russo ◽  
Rolf Baarholm
Keyword(s):  
Cross Flow ◽  
Effect Study ◽  
Full Scale ◽  
Scale Model ◽  
Small Scale ◽  
Scaling Effects ◽  
Research Activity ◽  
Forced Motion ◽  
Auxiliary Lines ◽  
Viv Suppression

For deep-water riser systems, Vortex Induced Vibrations (VIV) may cause significant fatigue damage. It appears that the knowledge gap of this phenomenon is considerable and this has caused a high level of research activity over the last decades. Small scale model tests are often used to investigate VIV behaviour. However, one substantial uncertainty in applying such results is scaling effects, i.e. differences in VIV response in full scale flow and small scale flow. To (partly) overcome this obstacle, a new innovative VIV test rig was designed and built at MARINTEK to test a rigid full scale riser model. The rigid riser model is mounted vertically and can either be elastically mounted or be given a forced motion. In the present version, the cylinder can only move in the cross-flow (CF) direction and is restricted in the in-line (IL) direction. The paper reports results from a drilling riser VIV experiment where the new rest rig has been used. The overall objective of the work is to study possible VIV suppression to improve operability of retrievable riser systems with auxiliary lines by adding riser fins. These fins are normally used as devices for protection of the auxiliary lines. The test program has recently been completed and analysis is an on-going activity. However, some results can be reported at this stage and more results are planned to be published. A bare riser model was used in a Reynolds number (Rn) scaling effect study. The riser model was elastically mounted and towed over a reduced velocity range around 4 – 10 in two different Rn ranges, 75 000 – 192 000 (subcritical regime) and 347 000 – 553 000 (critical regime). The difference in the displacement amplitude to diameter ratio, A/D, is found to be significant. The elastically mounted riser was also towed with various drilling riser configurations in order to study VIV/galloping responses. One configuration included a slick joint riser model with 6 kill & choke lines; another has added riser fins too. The riser model is based on a specific drilling riser and the kill and choke lines have various diameters and have a non-symmetrical layout. The various riser configurations have also been used in forced motion tests where the towed model has been given a sinusoidal CF motion. Forces have been measured. Determination of the force coefficients is still in progress and is planned to be reported later. Scaling effects appear to be a significant uncertainty and further research on the subject is recommended. The slick joint drilling riser configuration generally increased the displacements compared to displacements of the bare riser model. The drilling riser configuration with protection fins, kill and choke lines generally reduced the displacements compared to displacements of the bare riser model. For both riser systems, tests showed that the response is sensitive to the heading of the current.

Full scale model tests on slab track constructed on embankment

2012 ◽  
pp. 547-553 ◽  
Author(s):  
Jiang Hongguang ◽  
Bian Xuecheng ◽  
Chen Yunmin ◽  
Jiang Jianqun
Keyword(s):  
Model Tests ◽  
Full Scale ◽  
Scale Model ◽  
Slab Track

Small and Full-Scale Modeling for the Application of Wall Solar Chimneys

2016 ◽  
Author(s):  
David Park ◽  
Francine Battaglia
Keyword(s):  
Natural Ventilation ◽  
Velocity Ratio ◽  
Thermal Conditions ◽  
Ambient Air ◽  
Full Scale ◽  
Scale Model ◽  
Small Scale ◽  
Solar Chimney ◽  
Window Position ◽  
Pi Theorem

A solar chimney is a natural ventilation technique that has a potential to save energy consumption as well as to maintain the air quality in the building. However, studies of buildings are often challenging due to their large sizes. The objective of the current study was to determine relationships between small- and full-scale solar chimney system models. In the current work, computational fluid dynamics (CFD) was utilized to model different building sizes with a solar chimney system, where the computational model was validated with the experimental study of Mathur et al. The window, which controls entrainment of ambient air, was also studied to determine the effects of window position. Correlations for average velocity ratio and non-dimensional temperature were consistent regardless of window position. Buckingham pi theorem was employed to further non-dimensionalize the important variables. Regression analysis was conducted to develop a mathematical model to predict a relationship among all of the variables, where the model agreed well with simulation results with an error of 2.33%. The study demonstrated that the flow and thermal conditions in larger buildings can be predicted from the small-scale model.

Small‐Scale Model Tests of Structural Steel Assemblies

1989 ◽  
Vol 115 (8) ◽  
pp. 1999-2015 ◽  
Author(s):  
Benjamin J. Wallace ◽  
Helmut Krawinkler
Keyword(s):  
Structural Steel ◽  
Model Tests ◽  
Scale Model ◽  
Small Scale ◽  
Small Scale Model

scholarly journals Pile Model Tests Using Strain Gauge Technology

2015 ◽  
Vol 37 (3) ◽  
pp. 49-52 ◽  
Author(s):  
Adam Krasiński ◽  
Tomasz Kusio
Keyword(s):  
Bearing Capacity ◽  
Axial Force ◽  
Strain Gauge ◽  
Force Measurement ◽  
Ground Level ◽  
Model Tests ◽  
Scale Model ◽  
Small Scale ◽  
Pile Head ◽  
Pile Model

Abstract Ordinary pile bearing capacity tests are usually carried out to determine the relationship between load and displacement of pile head. The measurement system required in such tests consists of force transducer and three or four displacement gauges. The whole system is installed at the pile head above the ground level. This approach, however, does not give us complete information about the pile-soil interaction. We can only determine the total bearing capacity of the pile, without the knowledge of its distribution into the shaft and base resistances. Much more information can be obtained by carrying out a test of instrumented pile equipped with a system for measuring the distribution of axial force along its core. In the case of pile model tests the use of such measurement is difficult due to small scale of the model. To find a suitable solution for axial force measurement, which could be applied to small scale model piles, we had to take into account the following requirements: - a linear and stable relationship between measured and physical values, - the force measurement accuracy of about 0.1 kN, - the range of measured forces up to 30 kN, - resistance of measuring gauges against aggressive counteraction of concrete mortar and against moisture, - insensitivity to pile bending, - economical factor. These requirements can be fulfilled by strain gauge sensors if an appropriate methodology is used for test preparation (Hoffmann [1]). In this paper, we focus on some aspects of the application of strain gauge sensors for model pile tests. The efficiency of the method is proved on the examples of static load tests carried out on SDP model piles acting as single piles and in a group.

scholarly journals A SCHEMATIZATION OF ONSHORE-OFFSHORE TRANSPORT

1974 ◽  
Vol 1 (14) ◽  
pp. 51 ◽  
Author(s):  
D.H. Swart
Keyword(s):  
Sediment Transport ◽  
Sandy Beaches ◽  
Full Scale ◽  
Scale Model ◽  
Small Scale ◽  
Coastal Processes ◽  
Schematic Model ◽  
Empirical Relationships ◽  
Physically Based ◽  
Offshore Transport

The investigation reported herein covers two aspects of the schematization of coastal processes on sandy beaches in a direction perpendicular to the coastline, viz.: (1) the prediction of equilibrium beach profiles and (2) the corresponding offshore sediment transport due to wave action. A physically-based schematic model of the onshore-offshore profile development was tested on available small-scale and full-scale model tests and physically-based empirical relationships were derived to enable the application of the model to both small-scale and prototype conditions.

Controlling sand placement during the building of artificial islands

1984 ◽  
Vol 21 (2) ◽  
pp. 371-375 ◽  
Author(s):  
D. H. Shields ◽  
L. Domaschuk ◽  
D. W. Corkal ◽  
J. R. McCutchon
Keyword(s):  
Cost Saving ◽  
Low Cost ◽  
Model Tests ◽  
Scale Model ◽  
Small Scale ◽  
Considerable Cost ◽  
Environmentally Safe ◽  
Considerable Cost Saving ◽  
Small Scale Model

A new way to construct artificial islands of sand is described. The method shows promise of considerable cost saving. The present high cost of island building is due to the difficulty of making underwater sand slopes steep. Simply dumping sand into the ocean results in slopes of from 12 to 15 horizontal to 1 vertical. These shallow slopes have enormous implications in terms of sand volume and cost. The sand can be tremied into place to form a steep-sided ring or bund. Handling large quantities of sand in this way is expensive. Small-scale model tests show that if the sand is mixed with certain chemicals the resulting 'cohesion' enables the sand to fall through seawater as a block, with little dispersion. Steep underwater slopes result. Low-cost, nontoxic (environmentally safe) chemicals were used in the experiment. Keywords: construction, artificial islands, sand, oceans, dredging.

Pipeline plough performance in sand waves. Part 1: model testing

2010 ◽  
Vol 47 (1) ◽  
pp. 49-64 ◽  
Author(s):  
Mark Fraser Bransby ◽  
Michael Brown ◽  
Andrew Hatherley ◽  
Keith Lauder
Keyword(s):  
Model Testing ◽  
Model Tests ◽  
Scale Model ◽  
Soil Conditions ◽  
Small Scale ◽  
Offshore Pipelines ◽  
Sand Waves ◽  
Increased Risk ◽  
Small Scale Model ◽  
Spoil Heaps

Offshore pipelines are often buried in the seabed by ploughing a trench, placing the pipe at the base, and then backfilling. The ploughing operation is critical in terms of cost and project time, with increased risk due to uncertain soil conditions or geohazards. One problem that can be encountered is the presence of sand waves or megaripples on the seabed surface. This may affect the progress of the plough, prevent the plough from generating a level trench or modify the size of the spoil heaps for backfilling. These aspects have been investigated by conducting a series of small-scale model tests in the laboratory. These have revealed information about the plough kinematics and the resulting trench conditions when ploughing in sand waves with different wavelengths and amplitudes. It is shown that it may be possible to plough through regions of sand waves and estimate likely plough performance by knowing the sand wavelength and amplitude relative to the plough size.

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