Free‐Field Stress Gauge and Test Results in a New 1000 psi Dynamic Pressure Tank

Noise Control ◽  
1961 ◽  
Vol 7 (6) ◽  
pp. 4-10
Author(s):  
T. Winston ◽  
J. R. Stagner
Keyword(s):  
Dynamic Pressure ◽  
Free Field ◽  
Test Results ◽  
Field Stress ◽  
Pressure Tank

scholarly journals Analysis on the lateral vibration of drill string by mass effect of drilling fluid

2019 ◽  
Vol 10 (2) ◽  
pp. 363-371 ◽  
Author(s):  
Chunxu Yang ◽  
Ruihe Wang ◽  
Laiju Han ◽  
Qilong Xue
Keyword(s):  
Drilling Fluid ◽  
Dynamic Pressure ◽  
Mass Effect ◽  
Drill String ◽  
Natural Vibration Frequency ◽  
Lateral Vibration ◽  
Test Results ◽  
Additional Mass ◽  
Mass Coefficient ◽  
Fluid Environment

Abstract. It is well known that the influence of the internal and external drilling fluid on the lateral vibration characteristics of drillstring cannot be ignored. In this paper, experiment apparatus for simulating drillstring vibration was established. Hammering method is used to measure drillstring lateral natural vibration frequency when the internal and external drilling fluid is considered. The test results show that the drilling fluid can decrease the natural frequency of the drillstring. Based on the simulation model, considering the influence of the internal and external drilling fluid, an external drilling fluid additional mass coefficient is derived considering the dynamic pressure effect caused by external drilling fluid. Additional mass coefficient can get the result with high precision, which can meet the needs of the project. the simulation results are in good agreement with the test results, and the error is within 2 %. This work provides a useful attempt and lays the foundation for the dynamics of the drill string in the drilling fluid environment.

Initial Operating Experience and Test Results of ABB’s Gas Turbine GT13E2

1995 ◽  
Author(s):  
M. Klohr ◽  
J. Schmidtke ◽  
S. Tschirren ◽  
P. Rihak
Keyword(s):  
Gas Turbine ◽  
Dynamic Pressure ◽  
Operating Experience ◽  
Combined Cycle ◽  
Test Facility ◽  
Vibration Velocity ◽  
Inlet Temperature ◽  
Test Results ◽  
Pressure System ◽  
Annular Combustor

On 20 October 1993, the first ABB GT13E2 gas turbine was put into operation. This 165 MW class gas turbine achieves 35,7% thermal efficiency in single cycle application and up to 54,3% (according ISO standard 3977, Annexe F) in a three pressure system. An optimised turbine and compressor design along with the increased turbine inlet temperature, lead to improved efficiency and electrical output. A new concept for the combustor aimed at meeting the increasing demands on gas turbine emissions. The GT13E2 is equipped with the new single annular combustor and 72 of the ABB EV double cone burners. The commissioning and testing of the first GT13E2 was carried out at the Kawasaki Gas Turbine Research Center (KGRC) in Sodegaura City near Tokyo, Japan. The gas turbine was assembled with various measurement systems to monitor static and dynamic pressure, gas and metal temperature, expansion, vibration, velocity and emissions. The facility will be used during a 15 year joint test program by ABB and Kawasaki Heavy Industries (KHI) to obtain a sound database of operating experience for further improvements of the GT13E2 gas turbine. Therefore, mid 1994 a second test phase was conducted and early 1995 a third test period is scheduled. In parallel, the 2nd and 3rd GT13E2’s were commissioned and tested at the Deeside Combined Cycle Power Plant near Chester, Great Britain. In November 1994, the 4th GT13E2 at Lage Weide was successfully commissioned. This paper describes the operating experience with the GT13E2 during the first commissioning and test phases at KGRC and Deeside. The design features, the test facility, the instrumentation, the commissioning and test results are presented and discussed.

Research on Transonic Wind Tunnel Flutter Test for a Wing Model

2014 ◽  
Vol 1006-1007 ◽  
pp. 26-29
Author(s):  
Li Yu ◽  
Bin Bin Lv ◽  
Hong Tao Guo ◽  
Yu Yan ◽  
Xing Hua Yang ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
Dynamic Pressure ◽  
Critical Parameters ◽  
Test Results ◽  
Wing Model ◽  
Calibration And Verification ◽  
Observation Method ◽  
Prediction Approach ◽  
Direct Observation Method ◽  
Transonic Wind Tunnel

This paper adopts self-designed wing model to conduct flutter test on subsonic and transonic, and obtains flutter characteristic of the model, and the test results are used for calibration and verification of flutter procedures. The sub-critical extrapolation is used to obtain the flutter sub-critical parameters and the direct observation method is used to obtain comparison of results. Error of results obtained by the two approaches does not exceed 5%, and validates reliability of the sub-critical prediction approach in continuous adjusted dynamic pressure flutter test.

scholarly journals Fully Coupled FE Analyses of Buried Structures

1994 ◽  
Vol 1 (5) ◽  
pp. 451-460
Author(s):  
James T. Baylot
Keyword(s):  
Finite Element ◽  
Stress Analysis ◽  
Free Field ◽  
Scale Model ◽  
Response Analysis ◽  
Element Analysis ◽  
Buried Structures ◽  
Field Stress ◽  
Structure Response ◽  
Fully Coupled

Current procedures for determining the response of buried structures to the effects of the detonation of buried high explosives recommend decoupling the free-field stress analysis from the structure response analysis. A fully coupled (explosive–soil structure) finite element analysis procedure was developed so that the accuracies of current decoupling procedures could be evaluated. Comparisons of the results of analyses performed using this procedure with scale-model experiments indicate that this finite element procedure can be used to effectively evaluate the accuracies of the methods currently being used to decouple the free-field stress analysis from the structure response analysis.

Experimental Force Coefficients for Two Sealed Ends Squeeze Film Dampers (Piston Rings and O-Rings): An Assessment of Their Similarities and Differences

2018 ◽  
Vol 141 (2) ◽  
Author(s):  
Luis San Andrés ◽  
Bonjin Koo ◽  
Sung-Hwa Jeung
Keyword(s):  
Pressure Field ◽  
Dynamic Pressure ◽  
Added Mass ◽  
The Other ◽  
Squeeze Film ◽  
Test Results ◽  
Piston Rings ◽  
Force Coefficients ◽  
Supply Pressure ◽  
Squeeze Film Dampers

Squeeze film dampers (SFDs) in aircraft engines effectively aid to reduce rotor motion amplitudes, in particular when traversing a critical speed, and help to alleviate rotor whirl instabilities. The current work is a long-term endeavor focused on quantifying the dynamic force performance of practical SFDs, exploring novel design damper configurations, and producing physically sound predictive SFD models validated by experimental data. Piston rings (PRs) and O-rings (ORs), commonly used as end seals in SFDs for commercial and military gas turbine engines, respectively, amplify viscous damping in a short physical length and while operating with a modicum of lubricant flow. This paper presents experimental force coefficients (damping and inertia) for two identical geometry SFDs with end seals, one configuration hosts PRs, and the other one ORs. The test rig comprises a stationary journal and bearing cartridge (BC) hosting the SFD and supported on four elastic rods to emulate a squirrel cage. The damper film land length, diameter, and clearance are L = 25.4 mm, D = 5L, and c = 0.373 mm (D/c = 340), respectively. A supply feeds ISO VG 2 oil to the film land at its middle plane through either one hole or three holes, 2.5 mm in diameter, 120 deg apart. In the PRSFD, the lubricant exits through the slit opening at the ring butted ends. The ORs suppress oil leakage; hence, lubricant evacuates through a 1 mm hole at ¼ L near one journal end. The ORs when installed add significant stiffness and damping to the test structure. The ORSFD produces 20% more damping than the PRSFD, whereas both sealed ends SFDs show similar size added mass. For oil supplied at 0.69 bar(g) through a single orifice produces larger damping, 60–80% more than when the damper operates with three oil feedholes. A computational model reproducing the test conditions delivers force coefficients in agreement with the test data. Archival literature calls for measurement of a single pressure signal to estimate SFD reaction forces. For circular centered orbits (CCOs), the dynamic pressure field, in the absence of any geometrical asymmetry or feed/discharge oil condition, “rotates” around the bearing with a speed equal to the whirl frequency. The paper presents force coefficients estimated from (a) measurements of the applied forces and ensuing displacements, and (b) the dynamic pressure recorded at a fixed angular location and “integrated” over the journal surface. The first method delivers a damping coefficient that is large even with lubricant supplied at a low oil supply pressure whereas the inertia coefficient increases steadily with feed pressure. Predictions show good agreement with the test results from measured forces and displacements, in particular the added mass. On the other hand, identified damping and inertia coefficients from dynamic pressures show a marked difference from one pressure sensor to another, and vastly disagreeing with test results from the first method or predictions. The rationale for the discrepancy relies on local distortions in the dynamic pressure fields that show zones of oil vapor cavitation at a near zero absolute pressure and/or with air ingestion producing high frequency spikes from bubble collapsing; both phenomena depend on the magnitude of the oil supply pressure. An increase in lubricant supply pressure suppresses both oil vapor cavitation and air ingestion, which produces an increase of both damping and inertia force coefficients. No prior art compares the performance of a PRSFD vis-à-vis that of an ORSFD. Supplying lubricant with a large enough pressure (flow rate) is crucial to avoid the pervasiveness of air ingestion. Last, the discussion on force coefficients obtained from two distinct methods questions the use of an oversimplifying assumption; the dynamic pressure field is not invariant in a rotating coordinate frame.

Measurement of pressure in viewable hole erosion test

2018 ◽  
Vol 55 (10) ◽  
pp. 1502-1509 ◽  
Author(s):  
Liquan Xie ◽  
Xin Liang ◽  
Tsung-Chow Su
Keyword(s):  
Soil Mechanics ◽  
Dynamic Pressure ◽  
Test Results ◽  
Initial Profile ◽  
Monitoring Technique ◽  
Preliminary Model ◽  
Flow Test ◽  
Erosion Test ◽  
Piping Erosion ◽  
Shape Changes

The hole erosion test (HET) is commonly used to study the occurrence of internal soil erosion when water concentrated leaks occur. This erosion is known as “piping” in soil mechanics. Piping erosion is invisible and occurs randomly within the soil body. Therefore, to gain a better understanding of how piping erosion develops, it would be helpful to utilize a viewable HET design in which the dynamics of the piping hole can be observed directly. In this note, a new HET apparatus is presented that can be used to observe the development of piping erosion and to monitor the dynamic pressure condition during the hole erosion process. A preliminary model test was carried out based on the new viewable HET apparatus and “pressure heads” monitoring technique. The results successfully verified the performance of the proposed apparatus and experimental methods during the process of hole erosion, indicating that the hole shape changes during continuous erosion and is not fully symmetrical because of the initial profile of the hole. The internal hole becomes increasingly curved when subjected to continuous piping flow. Test results agree with the numerical simulation reported in 2015 by Riha and Jandora, who considered the effect of the hole entrance shape.

Experimental Force Coefficients for Two Sealed Ends Squeeze Film Dampers (Piston Rings and O-Rings): An Assessment of Their Similarities and Differences

2018 ◽  
Author(s):  
Luis San Andrés ◽  
Bonjin Koo ◽  
Sung-Hwa Jeung
Keyword(s):  
Pressure Field ◽  
Dynamic Pressure ◽  
Added Mass ◽  
The Other ◽  
Squeeze Film ◽  
Test Results ◽  
Piston Rings ◽  
Force Coefficients ◽  
Supply Pressure ◽  
Squeeze Film Dampers

Squeeze film dampers (SFDs) in aircraft engines effectively aid to reduce rotor motion amplitudes, in particular when traversing a critical speed, and help to alleviate rotor whirl instabilities. The current work is a long term endeavor focused on quantifying the dynamic force performance of practical SFDs, exploring novel design damper configurations, and producing physically sound predictive SFD models validated by experimental data. Piston rings (PRs) and O-rings (ORs), commonly used as end seals in SFDs for commercial and military gas turbine engines, respectively, amplify viscous damping in a short physical length and while operating with a modicum of lubricant flow. This paper presents experimental force coefficients (damping and inertia) for two identical geometry SFDs with end seals, one configuration hosts PRs, and the other one ORs. The test rig comprises a stationary journal and bearing cartridge (BC) hosting the SFD and supported on four elastic rods to emulate a squirrel cage. The damper film land length, diameter and clearance are L = 25.4 mm, D = 5L, and c = 0.373 mm (D/c = 340), respectively. A supply feeds ISO VG 2 oil to the film land at its middle plane through either one hole or three holes, 2.5 mm in diameter, 120° apart. In the PR-SFD, the lubricant exits thru the slit opening at the ring butted ends. The O-rings suppress oil leakage; hence, lubricant evacuates through a 1 mm hole at ¼ L near one journal end. The O-rings when installed add significant stiffness and damping to the test structure. The ORSFD produces 20% more damping than the PR-SFD, whereas both sealed ends SFDs show similar size added mass. For oil supplied at 0.69 bar(g) through a single orifice produces larger damping, 60% to 80% more than when the damper operates with three oil feedholes. A computational model reproducing the test conditions delivers force coefficients in agreement with the test data. Archival literature calls for measurement of a single pressure signal to estimate SFD reaction forces. For circular centered orbits, the dynamic pressure field, in the absence of any geometrical asymmetry or feed/discharge oil condition, “rotates” around the bearing with a speed equal to the whirl frequency. The paper presents force coefficients estimated from (a) measurements of the applied forces and ensuing displacements, and (b) the dynamic pressure recorded at a fixed angular location and “integrated” over the journal surface. The first method delivers a damping coefficient that is large even with lubricant supplied at a low oil supply pressure whereas the inertia coefficient increases steadily with feed pressure. Predictions show good agreement with the test results, in particular the added mass. On the other hand, identified damping and inertia coefficients from dynamic pressures show a marked difference from one pressure sensor to another, and vastly disagreeing with test results from the first method or predictions. The rationale for the discrepancy relies on local distortions in the dynamic pressure fields that show zones of oil vapor cavitation at a near zero absolute pressure and/or with air ingestion producing high frequency spikes from bubble collapsing; both phenomena depend on the magnitude of the oil supply pressure. An increase in lubricant supply pressure suppresses both oil vapor cavitation and air ingestion which produces an increase of both damping and inertia force coefficients. No prior art compares the performance of a PR-SFD vis-à-vis that of an OR-SFD. Supplying lubricant with a large enough pressure (flow rate) is crucial to avoid the pervasiveness of air ingestion. Lastly, the discussion on force coefficients obtained from two distinct methods questions the use of an oversimplifying assumption; the dynamic pressure field is not invariant in a rotating coordinate frame.

Acoustics Based Prognostics for DLE Combustor Lean Blowout Detection

2006 ◽  
Author(s):  
Avinash Taware ◽  
Minesh Shah ◽  
Pingchuan Wu ◽  
Yongsheng Yang ◽  
Jian Zhou ◽  
...  
Keyword(s):  
Gas Turbines ◽  
Lead Time ◽  
Dynamic Pressure ◽  
Low Frequency ◽  
Test Results ◽  
Fusion Algorithm ◽  
Lean Blowout ◽  
Fuel Flow ◽  
Low Emission ◽  
Relative Change

Physics based algorithm that uses acoustic precursors indicating a Lean Blowout (LBO) is proposed for lean blowout detection in combustors. The proposed technology is presented for a typical multi-nozzle Dry Low Emission (DLE) combustor. Three narrow band dynamic pressure tones, namely LBO (low frequency) tone, high fuel to air (F/A) ratio (hot tone) and low F/A ratio (cold) tones are identified as strong precursors to behavior consistent with combustion instability as LBO event evolves. The likelihood of LBO is computed using a statistical model operating on the RMS value of the LBO tone. Two additional pieces of evidential information are built respectively using the relative change of the RMS values of these three tones and the frequency shift of the high F/A tone. A data fusion algorithm then uses these two evidential signatures to enhance the LBO probability based on the LBO tone. Field test results on GE’s commercial multi-nozzle combustor gas turbines showed that the algorithm is practical and effective giving enough lead-time to take corrective action to avoid a blowout. A closed loop controller that modulates global manifold fuel splits for all the combustors or total fuel flow of individual combustor in a multi-combustor (multi-can) turbine to avoid the incipient blowout upon detection using the method presented in this paper can then be easily designed.

Development of a Predictive Method for Quantifying Vortex-Shedding Pulsation Amplitudes in Compressor Piping Systems

2015 ◽  
Author(s):  
Sarah Simons ◽  
Eugene L. Broerman ◽  
Klaus Brun
Keyword(s):  
Vortex Shedding ◽  
Experimental Testing ◽  
Dynamic Pressure ◽  
Operating Conditions ◽  
Piping System ◽  
Test Results ◽  
Pressure Data ◽  
Test Configuration ◽  
Predictive Method ◽  
Piping Systems

One of the design criteria for centrifugal compressor piping systems is the prevention of piping and valve failures from high pulsation amplitudes and vibration caused by vortex-shedding induced (VSI) pulsations of gas flow past closed piping branches (stubs). Most vortex-shedding analyses are performed on the basis of frequency avoidance. If a coincidence is predicted between the acoustic natural frequency of a piping segment and the flow induced vortex shedding frequency, piping changes must be made to avoid the coincidence, since there is currently no known method for accurately predicting the severity of the resulting pulsation amplitudes and, therefore, the possibility of piping failures. Often, these piping changes are expensive and time consuming and likely unnecessary for smaller bore piping (10-inch or less), assuming the flow-acoustic coincidence does not coincide with a mechanical resonance. The majority of research performed to date on vortex-shedding excitation of piping stubs focuses on predicting the frequencies of excitation using an experimentally determined Strouhal number or range of numbers for a given geometry or piping feature. However, to properly design a piping system using a combination of support structures and piping changes, reliable prediction of the pulsation amplitude is essential for determining the shaking forces acting on the piping system and the resulting vibration and stress amplitudes. Due to the expense of experimental testing and availability of equipment, it is difficult to obtain accurate amplitude measurements of VSI pulsations of fluids at Reynolds numbers typically associated with natural gas transmission. This paper describes a series of experimental tests performed to record vortex-shedding induced pulsation amplitudes in three test facilities. Three different process fluids were utilized varying the operating conditions to obtain gas flows with Reynold’s numbers between 1e5 and 2e7. Steady state flow, temperature and pressure data was recorded with ASME PTC-10 compliant instrumentation. Transient pressure data was taken with dynamic pressure transducers installed at each stub end as well as in the main piping near the tee. The geometry configurations, pulsation amplitudes, and calculated Strouhal numbers associated with each test configuration are presented. Comparison was made between the test results and several previously published formulas. From the test results, a predictive method was developed to best represent the limit of the pulsation amplitudes.

scholarly journals Combustion System Performance of a Water Injected MS7001E Gas Turbine Operating at a NOx Emission Level of 25 PPMVD

1990 ◽  
Author(s):  
David O. Fitts ◽  
Richard A. Symonds ◽  
Edmond R. Western
Keyword(s):  
Gas Turbine ◽  
System Performance ◽  
Mechanical Performance ◽  
Catalytic Reduction ◽  
Dynamic Pressure ◽  
Water Injection ◽  
Test Results ◽  
Combustion System ◽  
California Water ◽  
Unburned Hydrocarbons

This paper presents the results of emissions testing and combustion system dynamics testing of a “Quiet Combustor” equipped MS7001E gas turbine at the Midway Sunset Cogeneration Company in Fellows, California. Water injection is used to control NOx emissions to 25 ppmvd without selective catalytic reduction. Test results include NOx, CO, unburned hydrocarbons, VOC, and formaldehyde emissions levels, and combustor dynamic pressure levels. Combustion system hardware mechanical performance is described following the initial combustion system inspection.

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