NEW TEST RIG FOR MEASURING THE FRICTION TORQUE OF GEARBOXES IN EXTREME THERMAL CONDITIONS

Tribologia ◽  
2021 ◽  
Vol 296 (2) ◽  
pp. 57-64
Author(s):  
Waldemar Tuszyński ◽  
Marian Szczerek ◽  
Jan Wulczyński ◽  
Andrzej Gospodarczyk ◽  
Remigiusz Michalczewski ◽  
...  
Keyword(s):  
Mobile Device ◽  
Thermal Conditions ◽  
Friction Torque ◽  
Climatic Chamber ◽  
Test Rig ◽  
Lubricating Oils ◽  
Tribological Tests ◽  
Start Up

A new test rig for tribological tests was developed and manufactured. It consists of a mobile device for measurement of the start-up friction torque of transmissions, in particular planetary gearboxes, and the friction torque in dynamically steady conditions, as well as a climatic chamber to stabilize the temperature of the tested gearbox in its extreme range: from -50 to +50°C. In the series of devices for tribological tests, developed and manufactured at the Institute, the new test rig is marked with the symbol T-34. The verification results correspond with the churning losses related to the viscosity characteristics of the lubricating oils. As the temperature increases, both the start-up friction torque and the friction torque under dynamically steady conditions decrease.

scholarly journals Innovative Test Rig for Jet Fuels Thermal Stability Testing / Innowacyjne Stanowisko Badawcze Do Określania Stabilności Termicznej Paliw Lotniczych

2014 ◽  
Vol 29 (1) ◽  
pp. 15-22
Author(s):  
Jarosław Sarnecki
Keyword(s):  
Thermal Stability ◽  
Laboratory Test ◽  
Thermal Conditions ◽  
Standard Test ◽  
Test Method ◽  
Jet Fuels ◽  
Stability Testing ◽  
Test Rig ◽  
Standard Test Method ◽  
Laboratory Test Method

Abstract The article deals with laboratory test method for jet fuels thermal stability testing. Author described the reasons that led to test rig preparation, its construction and operation principles. Innovative test rig for jet fuels thermal stability testing enables research in wide thermal conditions and different pressures. Testing capabilities and advantages compared with currently used standard test method of jet fuels thermal stability testing according to ASTM D3241 have been also presented

scholarly journals Atypical start-up experiments on pump as turbine

2021 ◽  
Vol 13 (11) ◽  
pp. 168781402110627
Author(s):  
Yu-Liang Zhang ◽  
Yan-Juan Zhao
Keyword(s):  
Static Pressure ◽  
Power Coefficient ◽  
Transient Performance ◽  
Test Rig ◽  
Transient Characteristics ◽  
Maximum Value ◽  
Start Up ◽  
Initial Stage ◽  
Evolution Characteristics ◽  
The Impact

At present, research on the characteristics of pumps as turbine (PATs) during the start-up process is still insufficient. To reveal the transient characteristics of a centrifugal PAT during the atypical start-up process, a test rig for the transient performance of the PAT was built; in addition, experiments on the transient hydraulic performance of three kinds of steady speed and three kinds of steady flow were conducted. Through these experiments, the evolution characteristics of the transient performance parameters of the PAT during the atypical start-up process were analyzed over time. Moreover, three dimensionless coefficients were employed to deeply reveal the transient characteristics of the PAT during atypical start-up. Results showed that the rise curves of flow rate and outlet static pressure exhibited shock phenomena. With the increase in the stable running speed after start-up, the impact phenomenon of the outlet static pressure presented a delayed trend. The dimensionless head and flow coefficients reached the maximum value at the initial stage of the atypical start-up process and then rapidly dropped to the minimum value before slowly rising to the final stable value. The dimensionless power coefficient had a maximum value at the initial stage of atypical start-up and then rapidly dropped to the final stable value.

Experimental Analyses of a First Generation Foil Bearing: Start-Up Torque and Dynamic Coefficients

2010 ◽  
Author(s):  
Laurent Rudloff ◽  
Mihai Arghir ◽  
Olivier Bonneau ◽  
Pierre Matta
Keyword(s):  
Dynamic Characteristics ◽  
Static Load ◽  
Excitation Frequency ◽  
Base Plate ◽  
Test Rig ◽  
Dynamic Coefficients ◽  
Foil Bearing ◽  
Start Up ◽  
Lift Off ◽  
Stiffness And Damping

The paper presents the results of the experimental analysis of static and dynamic characteristics of a generation 1 foil bearing of 38.1 mm diameter and L/D = 1. The test rig is of floating bearing type, the rigid shaft being mounted on ceramic ball bearings and driven up to 40 krpm. Two different casings are used for start-up and for measurement of dynamic coefficients. In its first configuration, the test rig is designed to measure the start-up torque. The foil bearing casing is made of two rings separated by a needle bearing for enabling an almost torque free rotation between the foil bearing and the static load. The basic results are the start up torque and the lift off speed. In its second configuration a different casing is used for measuring the impedances of the foil bearing. Misalignment is a problem that is minimized by using three flexible stingers connecting the foil bearing casing to the base plate of the test rig. The test rig enables the application of a static load and of the dynamic excitation on the journal bearing casing, and can measure displacements, forces and accelerations. Working conditions consisted of static loads comprised between 10 N and 50 N and rotation frequencies ranging from 260 Hz to 590 HZ. Excitation frequencies comprised between 100 Hz are 600 Hz are applied by two orthogonally mounted shakers for each working condition. Stiffness and damping coefficients are identified from the complex impedances and enable the calculation of natural frequencies. The experimental results show that the dynamic characteristics of the tested bearing have a weak dependence on the rotation speed but vary with the excitation frequency.

Start up and control of a DFIG wind turbine test rig

2011 ◽  
Author(s):  
J.A. Cortajarena ◽  
J. De Marcos ◽  
P. Alvarez ◽  
F.J. Vicandi ◽  
P. Alkorta
Keyword(s):  
Wind Turbine ◽  
Test Rig ◽  
Start Up ◽  
And Control

Metallurgical Failure Analysis of Cracking in Exhaust Stack Liner Fastening Bolts

2021 ◽  
Vol 58 (10) ◽  
pp. 662-671
Author(s):  
A. Neidel ◽  
M. Giller ◽  
S. Riesenbeck
Keyword(s):  
Failure Analysis ◽  
Gas Turbine ◽  
Shear Loading ◽  
Mean Stress ◽  
Test Rig ◽  
Exhaust Gases ◽  
Start Up

Abstract Exhaust stack liners of a test rig for gas turbine burners failed locally by ruptured fasteners and fallen-off liner plates. Misalignment of the plating relative to each other and relative to their fasteners caused restraint of the expanding and shrinking liner plates upon start-up and shutdown of the burner rig. The fastening holes of the failed liner plates were not concentric, but misaligned relative to each other and relative to their fastener bolts. This exerted a shear loading on the threads of the fastening bolts, which in turn caused a mean stress shift and damaged the threads of the fasteners by nicking. So pre-loaded, the fastening bolts were not able to withstand the vibratory loads from the flowing exhaust gases and failed due to fatigue.

Experimental Analysis of the Dynamic Characteristics of a Foil Thrust Bearing

2014 ◽  
Author(s):  
Franck Balducchi ◽  
Mihai Arghir ◽  
Romain Gauthier
Keyword(s):  
Dynamic Characteristics ◽  
Experimental Analysis ◽  
Dynamic Models ◽  
Thrust Bearing ◽  
Dynamic Stiffness ◽  
Excitation Frequency ◽  
Test Rig ◽  
Equivalent Damping ◽  
Start Up ◽  
Foil Thrust Bearing

The paper deals with the experimental analysis of the dynamic characteristics of a foil thrust bearing (FTB) designed following the specifications given by NASA in 2009. The start-up characteristics of the same foil bearing were investigated in a recently published paper. The test rig used for start-up measurements was adapted for dynamic measurements. The paper presents the test rig in detail as well as its identified dynamic models. Measurements of the dynamic characteristics of the bump foil structure were performed for static loads comprised between 30 N and 150 N while measurements for the FTB were performed at 35 krpm for 30 N, 60 N and 90 N. Excitation frequencies were comprised between 150 Hz and 750 Hz. Results showed that the dynamic stiffness of the FTB increase with excitation frequency while the equivalent damping decreases. Both stiffness and damping increase with the static load but are smaller at 35 krpm compared to 0 rpm.

Hybrid System Test Rig: Start-up and Shutdown Physical Emulation

2010 ◽  
Vol 7 (2) ◽  
Author(s):  
Mario L. Ferrari ◽  
Matteo Pascenti ◽  
Loredana Magistri ◽  
Aristide F. Massardo
Keyword(s):  
Control System ◽  
Thermal Stress ◽  
High Temperature ◽  
Fuel Cell ◽  
Hybrid System ◽  
Cell Hybrid ◽  
Test Rig ◽  
Start Up ◽  
Outlet Flow ◽  
Integrated Project

The University of Genoa (TPG) has designed and developed an innovative test rig for high temperature fuel cell hybrid system physical emulation. It is based on the coupling of a modified commercial 100 kW recuperated micro gas turbine to a special modular volume designed for the experimental analysis of the interaction between different dimension fuel cell stacks and turbomachines. This new experimental approach that generates reliable results as a complete test rig also allows investigation of high risk situations with more flexibility without serious and expensive consequences to the equipment and at a very low cost compared with real hybrid configurations. The rig, developed with the support of the European Integrated Project “FELICITAS,” is under exploitation and improvement in the framework of the new European Integrated Project “LARGE-SOFC” started in January 2007. The layout of the system (connecting pipes, valves, and instrumentation) was carefully designed to minimize the pressure loss between compressor outlet and turbine inlet to have the highest plant flexibility. Furthermore, the servocontrolled valves are useful for performing tests at different operative conditions (i.e., pressures, temperatures, and pressure losses), focusing the attention on surge and thermal stress prevention. This work shows the preliminary data obtained with the machine connected to the volume for the test rig safe management to avoid surge or excessive stress, especially during the critical operative phases (i.e., start-up and shutdown). Finally, the attention is focused on the valve control system developed to emulate the start-up and shutdown phases for high temperature fuel cell hybrid systems. It is necessary to manage the flows in the connecting pipes, including an apt recuperator bypass, to perform a gradual heating up and cooling down as requested during these phases. It is an essential requirement to avoid thermal stress for the fuel cell stack. For this reason, during the start-up, the volume is gradually heated by the compressor outlet flow followed by a well managed recuperator outlet flow and vice versa for the shutdown. Furthermore, operating with a constant rotational speed control system, the machine load is used to reach higher temperature values typical of these kinds of systems.

An Experimental Study of Transient Thermal Effects in a Plain Journal Bearing

1999 ◽  
Vol 121 (2) ◽  
pp. 327-332 ◽  
Author(s):  
B. Kucinschi ◽  
M. Fillon
Keyword(s):  
Thermal Effects ◽  
Journal Bearing ◽  
Friction Torque ◽  
Oil Viscosity ◽  
Fluid Friction ◽  
Start Up ◽  
Alumel Thermocouple ◽  
Bearing Loads ◽  
Transient Thermal

The present study deals with the experimental determination of temperature distribution in a plain, steadily loaded journal bearing, during transient thermal periods such as start-up or slow changing in velocity. A number of chromel-alumel thermocouples, placed circumferentially in the median section of the bearing, are used in order to carry out the measurements. The temperature at film-shaft interface is also measured by means of a chromel-alumel thermocouple and a mercury transmitter. The effects of journal speed and load on bearing temperature and fluid friction torque are analyzed. The bearing temperature increases considerably with the increase of rotational speed. In addition, for slight bearing loads the bearing temperatures are greater than for higher loads, due to the oil recirculation. The fluid friction torque increases at start-up and afterwards tends to decrease because of the temperature rise which decreases the oil viscosity.

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