Experimental Investigation of the Shear Strength of Lubricants Subjected to High Pressure and Temperature

1986 ◽  
Vol 108 (4) ◽  
pp. 571-577 ◽  
Author(s):  
E. Ho¨glund ◽  
B. Jacobson
Keyword(s):  
Experimental Investigation ◽  
High Pressure ◽  
Shear Strength ◽  
High Pressure And Temperature ◽  
Mineral Oils ◽  
Wide Range ◽  
Experimental Apparatus ◽  
Synthetic Lubricants ◽  
The Relationship ◽  
Natural And Synthetic

In order to evaluate the relationship between limiting shear strength and pressure for a lubricant an experimental apparatus has been built. Pressures up to 2.2 GPa and temperatures up to 200°C are attainable simultaneously. Thus the limiting shear strength-pressure relationship has been surveyed in a wide range. Several types of natural and synthetic lubricants have been tested. The results show that all the mineral oils tested behave in quite a similar way. Synthetic lubricants do not show this behaviour, but the relationship between limiting shear strength and pressure depends strongly upon the chemical base of the synthetic lubricants. The behaviour of grease does not differ from that of liquid lubricants. The pressures at which the lubricants change from a liquid to a solid behaviour have also been measured.

scholarly journals Relationship between shear strength and surface roughness of double-layered pipes by cold drawing

2021 ◽  
Vol 12 (1) ◽  
pp. 123-131
Author(s):  
Moktan Ahn ◽  
Joonhong Park
Keyword(s):  
Surface Roughness ◽  
High Pressure ◽  
Shear Strength ◽  
Fem Analysis ◽  
Cold Drawing ◽  
Shear Strength Test ◽  
Marine Plants ◽  
Pressure Resistance ◽  
Single Pipe ◽  
The Relationship

Abstract. Pipes applied to marine plants are used in deep-sea environments; therefore, they must be resistant to high pressure and corrosion. Because it is difficult to satisfy both of these factors in a single pipe, studies on a double-layered pipe are continuously being performed. An outer pipe should be made of carbon steel, with high pressure resistance, and an inner pipe should be made of stainless steel, with high corrosion resistance. A pipe formed by combining these two pipes is called a lined pipe. The shear strength of the lined pipe is an important factor because pipe cracking can occur due to stress concentration when two pipes are separated by bending or high pressure. Therefore, various processes have been applied to increase the shear strength. In this paper, we investigate the effect of the surface roughness of the bonding interface on the shear strength. Surface roughness is in units of micrometers, and it cannot be used for finite element method (FEM) analysis. Therefore, surface roughness should be converted into a friction coefficient to perform FEM analysis. The effect of surface roughness on shear strength was studied in the relationship between the results of pressure from FEM analysis and the shear strength test.

Experimental Investigation and Numerical Simulation of Gas Ejector in a Combustor With Combustion Gases Recirculation

2003 ◽  
Author(s):  
Kumpeng Zhang ◽  
Fei Xue ◽  
Weiming Pan ◽  
Zhihua Fan
Keyword(s):  
Numerical Simulation ◽  
Experimental Investigation ◽  
High Pressure ◽  
Area Ratio ◽  
Gas Pressure ◽  
Pressure Condition ◽  
Combustion Gases ◽  
Ejection Coefficient ◽  
Pressure Changes ◽  
The Relationship

Sets of high-pressure ejection experiment were conducted to investigate the implementing of gases ejector with high-pressure condition. Numerical simulation was used to extend the study and overcome the limit of experiment facilities. Experiment shows that ejection coefficient of gases ejector was not sensitive to supply gas pressure changes. But which was affected greatly by backpressure in mixing cavity of ejector, as shown by simulation. The simulation result also implies that there are inherent relation between ejection coefficient, area ratio at inlet of mixing cavity and pressure different between supply gas pressure and the backpressure. And the relationship determines that in some range, the implementing of gas ejector was unstable.

Experimental Investigation of Self-Excited Combustion Instabilities in a Lean, Premixed, Gas Turbine Combustor at High Pressure

2017 ◽  
Author(s):  
Timo Buschhagen ◽  
Rohan Gejji ◽  
John Philo ◽  
Lucky Tran ◽  
J. Enrique Portillo Bilbao ◽  
...  
Keyword(s):  
Experimental Investigation ◽  
High Pressure ◽  
Operating Conditions ◽  
Chamber Pressure ◽  
Dynamic Mode ◽  
Combustion Instabilities ◽  
Compression Phase ◽  
Wide Range ◽  
Lower Amplitude ◽  
Lean Premixed

An experimental investigation of self-excited combustion instabilities in a high pressure, single-element, lean, premixed, natural gas dump-combustor is presented in this paper. The combustor is designed for optical access and is instrumented with high frequency pressure transducers at multiple axial locations. A parametric survey of operating conditions including inlet air temperature and equivalence ratio has been performed, which presents a wide range of peak to peak pressure fluctuations (p′) of the mean chamber pressure (pc). Two cases, Flame A and B with p′ /pc = 28% and p′/pc = 15% respectively, both presenting self-excited instabilities at the fundamental longitudinal (1L) mode of the combustion chamber, are discussed to study the coupling mechanism between flame-vortex interactions and the acoustic field in the chamber. OH*-chemiluminescence is used to obtain a map of global heat release distribution in the combustor. Phase conditioned analysis and Dynamic Mode Decomposition (DMD) analysis is performed, to highlight the contrasting mechanisms that lead to the two distinct instability regimes. Flame interactions with shear layer vortex structures just downstream of the dump plane during the compression phase of the acoustic cycle are found to augment the instability amplitude. Flame A engages strongly in this coupling, whereas Flame B is less affected and establishes a lower amplitude limit cycle.

Experimental Investigation of Flexure Properties for High-Strength Corrugated Composite Paperboard

2012 ◽  
Vol 200 ◽  
pp. 175-179
Author(s):  
Shi Bao Wen
Keyword(s):  
Experimental Investigation ◽  
Shear Strength ◽  
Sandwich Structure ◽  
Transverse Direction ◽  
High Strength ◽  
Face Sheet ◽  
Flexure Strength ◽  
Yield Load ◽  
The Relationship

In order to investigate flexure properties of high-strength corrugated composite paperboard(HCCP), applying the method of flexure property test for sandwich structure, four kinds of thickness paperboard –10,15,20 and 30mm– were tested according to longitudinal and transverse direction respectively, then the curve of flexure load – deflection was analyzed, the paper focused on the relationship between flexure yield load, flexure strength of face sheet, shear strength of core and thickness and direction of paperboard. The investigation has a strong significance for HCCP’s application in practice.

scholarly journals Formation of Spessartine and CO2 via Rhodochrosite Decarbonation along a Hot Subduction P-T Path

Minerals ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 703
Author(s):  
Yuliya V. Bataleva ◽  
Aleksei N. Kruk ◽  
Ivan D. Novoselov ◽  
Yuri N. Palyanov
Keyword(s):  
High Pressure ◽  
Isotopic Signature ◽  
Experimental Simulation ◽  
Fluid Composition ◽  
Raman Spectroscopic ◽  
Wide Range ◽  
T Path ◽  
The Relationship ◽  
Subducting Slab ◽  
High Pressure Apparatus

Experimental simulation of rhodochrosite-involving decarbonation reactions resulting in the formation of spessartine and CO2-fluid was performed in a wide range of pressures (P) and temperatures (T) corresponding to a hot subduction P-T path. Experiments were carried out using a multi-anvil high-pressure apparatus of a “split-sphere” type (BARS) in an MnCO3–SiO2–Al2O3 system (3.0–7.5 GPa, 850–1250 °C and 40–100 h.) with a specially designed high-pressure hematite buffered cell. It was experimentally demonstrated that decarbonation in the MnCO3–SiO2–Al2O3 system occurred at 870 ± 20 °C (3.0 GPa), 1070 ± 20 °C (6.3 GPa), and 1170 ± 20 °C (7.5 GPa). Main Raman spectroscopic modes of the synthesized spessartine were 349–350 (R), 552(υ2), and 906–907 (υ1) cm−1. As evidenced by mass spectrometry (IRMS) analysis, the fluid composition corresponded to pure CO2. It has been experimentally shown that rhodochrosite consumption to form spessartine + CO2 can occur at conditions close to those of a hot subduction P-T path but are 300–350 °C lower than pyrope + CO2 formation parameters at constant pressures. We suppose that the presence of rhodocrosite in the subducting slab, even as solid solution with Mg,Ca-carbonates, would result in a decrease of the decarbonation temperatures. Rhodochrosite decarbonation is an important reaction to explain the relationship between Mn-rich garnets and diamonds with subduction/crustal isotopic signature.

Elastohydrodynamic Film Thickness in Concentrated Contacts: Part 1: Experimental Investigation for Lubricant Entrainment Aligned with the Major Axis of the Contact Ellipse

1986 ◽  
Vol 200 (3) ◽  
pp. 207-217 ◽  
Author(s):  
R J Chittenden ◽  
D Dowson ◽  
C M Taylor
Keyword(s):  
Experimental Investigation ◽  
Film Thickness ◽  
Major Axis ◽  
Lubricant Film ◽  
Capacitance Measurement ◽  
Experimental Investigations ◽  
Lubricant Film Thickness ◽  
Wide Range ◽  
Experimental Apparatus ◽  
Contact Ellipse

Experimental investigations of the lubricant film thickness generated in elastohydrodynamic elliptical contacts have been undertaken since the early 1960s. The majority of these studies has been concerned with circular or near circular contact situations, although a wide range of geometries in which lubricant entrainment was directed along the minor axis of the contact ellipse has also been considered. The information available on lubricant film thickness in geometrical conditions where lubricant entrainment was aligned with the major axis of the contact ellipse has, however, been severely limited. The experimental investigation described in this paper is therefore concerned with the measurement of lubricant film thickness in the unusual geometrical conditions recently analysed theoretically by the authors (1, 2). The measurements were made with the aid of a twin disc machine for geometries ranging from a radius ratio of unity down to a value of 0.112. The experimental apparatus is described and details are given of the special test discs which were manufactured to produce such geometries. The capacitance measurement technique adopted is detailed along with the numerical model developed to allow the measured values of inter-disc capacitance to be interpreted in terms of the lubricant film thickness. The lubricant film thickness developed in four geometrical situations was investigated at four rotational speeds and five loads. This allowed a comparison to be made with the film thickness values predicted by recent elastohydrodynamic theory for changes in both speed and load. The film thickness deduced from the capacitance measurements was considered to be representative of that found at the centre of contact, and good agreement was found between experiment and all aspects of the theoretical predictions.

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