Elimination of Turbine Erosion in the T56 Turboprop Engine

1965 ◽  
Author(s):  
J. G. Tomlinson ◽  
L. N. Montgomery
Keyword(s):  
Direct Evidence ◽  
Carbon Particle ◽  
Quantitative Measure ◽  
Operating Conditions ◽  
Test Method ◽  
Test Results ◽  
Fuel Type ◽  
Carbon Particles ◽  
Turboprop Engine ◽  
Service Operation

Turbine erosion was encountered in service operation with the T56 turboprop engine. Combustor carboning was suspected to be the cause of the problem. No direct evidence of carboning had been observed during development or in more than one million hours of service operation. An accelerated investigation was initiated to establish a quantitative measure of carbon particles in the combustor exhaust gases. A unique test method was developed to collect carbon particles on a component combustor test rig. Evaluations were conducted with the carbon collector to determine the effects of fuel nozzles, fuel type, operating conditions, and combustor configuration on carbon particle output. The combustor configuration was found to be the most important factor in the control of the problem. Combustor carboning was established as the cause of turbine erosion and a combustion liner modification was developed for service release. Service tests were conducted to correlate development test results and to verify that turbine erosion was eliminated with the modified combustion lines.

Lubricant Influence on Gear Efficiency

2009 ◽  
Author(s):  
Klaus Michaelis ◽  
Bernd-Robert Ho¨hn ◽  
Andreas Doleschel
Keyword(s):  
Power Loss ◽  
Energy Savings ◽  
Operating Conditions ◽  
Test Method ◽  
Test Results ◽  
Additive Package ◽  
Mean Values ◽  
Base Oil ◽  
Power Loss Reduction ◽  
Gear Efficiency

Power loss in a transmission is strongly related to the properties of the gear lubricant. Viscosity of the lubricant determines the no-load splash and churning losses. The losses in the EHD regime depend on the base oil type. In the boundary and mixed lubrication regime losses are mainly related to the chemical composition of the additive system. A test method was developed to evaluate the frictional properties of candidate transmission lubricants in relation to a mineral reference oil ISO VG 100 with a typical sulphur-phosphorus additive package. The test results can be expressed in simple correlation factors for no-load, EHD and boundary lubrication conditions, in comparative steady-state temperature development for given mean values of operating conditions, and in a ranking scale of different candidates. For a more detailed analysis of the expected power loss in a transmission in practice the results of the efficiency test can be introduced into an equation for the mean coefficient of gear friction for the respective oil. Thus the test results can be applied to any gear in practice at any operating conditions for any gear geometry. Examples of the influence of viscosity, base oil and additive type on the frictional behavior of gear lubricants and their effect on power loss reduction and energy savings in a gearbox are discussed.

Comparative Study of a Felt Abradable Seal

2018 ◽  
Author(s):  
Dan Hasnedl ◽  
Premysl Epikaridis
Keyword(s):  
State Of The Art ◽  
Analytical Formula ◽  
Operating Conditions ◽  
Test Method ◽  
Experimental Comparison ◽  
Maximum Efficiency ◽  
Test Results ◽  
Test Rig ◽  
New Type ◽  
Efficiency Gap

In turbo-machinery, abradable layers are used to protect sensible components while keeping minimal possible clearances for maximum efficiency. This article describes the experimental comparison of state of the art abradable layers used as steam turbine seals and a new type of abradable layer made of a metallic felt. The comparison is done via abradability and leakage testing. The leakage is also compared to a state of the art analytical formula to show the effect on the thermal cycle calculation. An abradable test rig is presented together with the test method. Test results show the value of the Felt seal compared to other two types at low contact speed area. A steam test rig is also presented. Seal leakage at real operating conditions is evaluated and compared to an analytical formula. The leakage results show some efficiency gap compared to other two types of seals.

Investigations of Road Wear Caused by Studded Tires

2014 ◽  
Vol 42 (1) ◽  
pp. 2-15
Author(s):  
Johannes Gültlinger ◽  
Frank Gauterin ◽  
Christian Brandau ◽  
Jan Schlittenhard ◽  
Burkhard Wies
Keyword(s):  
Traffic Safety ◽  
Test Bench ◽  
Operating Conditions ◽  
Test Method ◽  
Analytical Models ◽  
The Road ◽  
Driving Speed ◽  
Major Factors ◽  
Tire Friction ◽  
Variable Operating Conditions

ABSTRACT The use of studded tires has been a subject of controversy from the time they came into market. While studded tires contribute to traffic safety under severe winter conditions by increasing tire friction on icy roads, they also cause damage to the road surface when running on bare roads. Consequently, one of the main challenges in studded tire development is to reduce road wear while still ensuring a good grip on ice. Therefore, a research project was initiated to gain understanding about the mechanisms and influencing parameters involved in road wear by studded tires. A test method using the institute's internal drum test bench was developed. Furthermore, mechanisms causing road wear by studded tires were derived from basic analytical models. These mechanisms were used to identify the main parameters influencing road wear by studded tires. Using experimental results obtained with the test method developed, the expected influences were verified. Vehicle driving speed and stud mass were found to be major factors influencing road wear. This can be explained by the stud impact as a dominant mechanism. By means of the test method presented, quantified and comparable data for road wear caused by studded tires under controllable conditions can be obtained. The mechanisms allow predicting the influence of tire construction and variable operating conditions on road wear.

scholarly journals Comprehensive Parameters Identification and Dynamic Model Validation of Interior-Mount Line-Start Permanent Magnet Synchronous Motors

Machines ◽  
2019 ◽  
Vol 7 (1) ◽  
pp. 4 ◽  
Author(s):  
Luqman S. Maraaba ◽  
Zakariya M. Al-Hamouz ◽  
Abdulaziz S. Milhem ◽  
Ssennoga Twaha
Keyword(s):  
Mathematical Model ◽  
Permanent Magnet ◽  
High Efficiency ◽  
Experimental Tests ◽  
Induction Machines ◽  
Test Methods ◽  
Operating Conditions ◽  
Test Method ◽  
Permanent Magnet Synchronous Motors ◽  
Synchronous Motors

The application of line-start permanent magnet synchronous motors (LSPMSMs) is rapidly spreading due to their advantages of high efficiency, high operational power factor, being self-starting, rendering them as highly needed in many applications in recent years. Although there have been standard methods for the identification of parameters of synchronous and induction machines, most of them do not apply to LSPMSMs. This paper presents a study and analysis of different parameter identification methods for interior mount LSPMSM. Experimental tests have been performed in the laboratory on a 1-hp interior mount LSPMSM. The measurements have been validated by investigating the performance of the machine under different operating conditions using a developed qd0 mathematical model and an experimental setup. The dynamic and steady-state performance analyses have been performed using the determined parameters. It is found that the experimental results are close to the mathematical model results, confirming the accuracy of the studied test methods. Therefore, the output of this study will help in selecting the proper test method for LSPMSM.

Hysteresis loss of ultra-large off-the-road tire rubber compounds based on operating conditions at mine sites

2021 ◽  
pp. 095440702110155
Author(s):  
Shaosen Ma ◽  
Guangping Huang ◽  
Khaled Obaia ◽  
Soon Won Moon ◽  
Wei Victor Liu
Keyword(s):  
Large Strain ◽  
Tensile Tests ◽  
Operating Conditions ◽  
Hysteresis Loss ◽  
Strain Rates ◽  
Test Results ◽  
Tire Rubber ◽  
The Road ◽  
Rubber Compounds ◽  
Mine Sites

The objective of this study is to investigate the hysteresis loss of ultra-large off-the-road (OTR) tire rubber compounds based on typical operating conditions at mine sites. Cyclic tensile tests were conducted on tread and sidewall compounds at six strain levels ranging from 10% to 100%, eight strain rates from 10% to 500% s−1 and 14 rubber temperatures from −30°C to 100°C. The test results showed that a large strain level (e.g. 100%) increased the hysteresis loss of tire rubber compounds considerably. Hysteresis loss of tire rubber compounds increased with a rise of strain rates, and the increasing rates became greater at large strain levels (e.g. 100%). Moreover, a rise of rubber temperatures caused a decrease in hysteresis loss; however, the decrease became less significant when the rubber temperatures were above 10°C. Compared with tread compounds, sidewall compounds showed greater hysteresis loss values and more rapid increases in hysteresis loss with the rising strain rate.

scholarly journals Methodology for Selecting the Operating Conditions of a Vibration Generator Used in the Hot-Dip Galvanizing Process

Materials ◽  
2021 ◽  
Vol 14 (8) ◽  
pp. 2042
Author(s):  
Wojciech Kacalak ◽  
Igor Maciejewski ◽  
Dariusz Lipiński ◽  
Błażej Bałasz
Keyword(s):  
Simulation Model ◽  
Asynchronous Motor ◽  
Experimental Tests ◽  
Suspension System ◽  
Operating Conditions ◽  
Test Results ◽  
Forced Simulation

A simulation model and the results of experimental tests of a vibration generator in applications for the hot-dip galvanizing process are presented. The parameters of the work of the asynchronous motor forcing the system vibrations were determined, as well as the degree of unbalance enabling the vibrations of galvanized elements weighing up to 500 kg to be forced. Simulation and experimental tests of the designed and then constructed vibration generator were carried out at different intensities of the unbalanced rotating mass of the motor. Based on the obtained test results, the generator operating conditions were determined at which the highest values of the amplitude of vibrations transmitted through the suspension system to the galvanized elements were obtained.

Pulsed NMR for Molecular Structure Analysis of EPDM

1989 ◽  
Vol 62 (4) ◽  
pp. 643-655
Author(s):  
Richard W. Tomlinson ◽  
Daniel F. Sheridan
Keyword(s):  
Tensile Strength ◽  
Relaxation Times ◽  
Operating Conditions ◽  
Test Method ◽  
Major Contributor ◽  
Nmr Analysis ◽  
Pulsed Nmr ◽  
Molecular Structure Analysis ◽  
Separate Calibration ◽  
Comparison Data

Abstract The use of pulsed NMR analysis under proper operating conditions has proven to be useful for controlling various polymer compositions in the manufacture of EPDM. It can be used in determining the amount of oil incorporated into oil-extended EPDMs. At higher oil contents, the differences in EPDM properties will affect this test method, which will require a separate calibration curve for each type of polymer. It can be used to measure the propylene content of EPDM. Comparison data have shown that this technique is more accurate in predicting crystallinity or propylene content than the standard IR method within the propylene range of 22 to 41%. Pulsed NMR can also be used to predict uncured EPDM compound tensile strength and EPDM/PP compression-molded tensile strength. Since these properties are affected by the crystallinity of EPDM, of which percent ethylene is the major contributor, then tensile strength can be determined indirectly. Based on the tensile and SER correlation, it seems obvious that this technique is measuring the spin-spin relaxation times of the crystalline phase, whereas the ir method is only measuring propylene content.

A Self-Correcting and Self-Checking Gas Turbine Meter

1982 ◽  
Vol 104 (2) ◽  
pp. 143-149 ◽  
Author(s):  
W. F. Z. Lee ◽  
D. C. Blakeslee ◽  
R. V. White
Keyword(s):  
Gas Turbine ◽  
Operating Conditions ◽  
Exit Angle ◽  
Test Results ◽  
Main Rotor ◽  
Calibration Accuracy

A new metering concept of a self-correcting and self-checking turbine meter is described in which a sensor rotor downstream from the main rotor senses and responds to changes in the exit angle of the fluid leaving the main rotor. The output from the sensor rotor is then electronically combined with the output from the main rotor to produce an adjusted output which automatically and continuously corrects to original meter calibration accuracy. This takes place despite changes in retarding torques, bearing wear and/or upstream conditions occurring in field operations over those which were experienced during calibration. The ratio of the sensor rotor output to the main rotor output at operating conditions is also automatically and continuously compared with that at calibration conditions. This provides an indication of the amount of accuracy deviation from initial calibration that is being corrected by the sensor rotor. This concept is studied theoretically and experimentally. Both the theory and test results (laboratory and field) confirm the concept’s validity and practicability.

Experimental and Theoretical Rotordynamic Characteristics of a Hybrid Journal Bearing

1997 ◽  
Vol 119 (1) ◽  
pp. 132-141 ◽  
Author(s):  
J. T. Sawicki ◽  
R. J. Capaldi ◽  
M. L. Adams
Keyword(s):  
Journal Bearing ◽  
Operating Conditions ◽  
Dynamic Force ◽  
Test Results ◽  
Force Measurements ◽  
Lubrication Equation ◽  
Load Cells ◽  
Theoretical Predictions ◽  
Stiffness And Damping

This paper describes an experimental and theoretical investigation of a four-pocket, oil-fed, orifice-compensated hydrostatic bearing including the hybrid effects of journal rotation. The test apparatus incorporates a double-spool-shaft spindle which permits independent control over the journal spin speed and the frequency of an adjustable-magnitude circular orbit, for both forward and backward whirling. This configuration yields data that enables determination of the full linear anisotropic rotordynamic model. The dynamic force measurements were made simultaneously with two independent systems, one with piezoelectric load cells and the other with strain gage load cells. Theoretical predictions are made for the same configuration and operating conditions as the test matrix using a finite-difference solver of Reynolds lubrication equation. The computational results agree well with test results, theoretical predictions of stiffness and damping coefficients are typically within thirty percent of the experimental results.

The Research of IC Test Based on LTX-77 Test System

2014 ◽  
Vol 496-500 ◽  
pp. 1176-1179
Author(s):  
Li Tan ◽  
Yu Fang
Keyword(s):  
Test Object ◽  
Test System ◽  
Test Method ◽  
Test Results ◽  
Analog Ic ◽  
Test Platform ◽  
Logic Functions ◽  
Actual Test ◽  
Ic Test

LTX-77 test system is a large IC test system that is used for various kinds of analog IC, digital IC and analog digital mixed IC. It can be used to test DC parameters, AC parameters and logic functions. In the paper, the IC test platform is LTX-77 test system. IC ADC0804 was tested as the test object. The test method of IC is described in the view of actual test. The test results show that the test system is convenient and accurate, which has important practical value for IC manufacturers and users.

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