scholarly journals TRIBOLOGICAL CHARACTERISTICS OF ‘STEEL – CERAMICS-IRRADIATED-BY-HELIUM-IONS’ PAIR

2021 ◽  
pp. 44-50
Author(s):  
V.I. Butenko ◽  
S.N. Dubniuk ◽  
A.F. Dyachenko ◽  
K.V. Pavlii ◽  
B.V. Zajtsev
Keyword(s):  
Friction Factor ◽  
Linear Accelerator ◽  
Sliding Friction ◽  
Experimental Results ◽  
Density Change ◽  
Tribological Characteristics ◽  
Helium Ions ◽  
Calculation Data ◽  
Ceramic Samples ◽  
Factor Measurement

Facility for the tribological characteristics studying of a metal – ceramics pair and parameters of ceramic samples irradiation on the helium ions linear accelerator with energies 0.12 and 4 MeV are resulted. Profiles of damageability and occurrence of target atoms along of helium ions range are calculated for the irradiated TiO2 and Al2O3. Sputtering ratios and dependence of the sputtered atoms quantity on samples thickness are received. Calculations on density change of the irradiated samples are made. Experimental results of a sliding friction factor measurement depending on cycle’s quantity, temperature and irradiation doses are presented. On the basis of microscopic researches and calculation data conclusions are drawn about irradiation influence on interacting pair’s tribological characteristics.

Structural and magnetic study of the Ti4+-doped barium hexaferrite ceramic samples: Theoretical and experimental results

2011 ◽  
Vol 406 (17) ◽  
pp. 3130-3136 ◽  
Author(s):  
P.A. Mariño-Castellanos ◽  
A.C. Moreno-Borges ◽  
G. Orozco-Melgar ◽  
J.A. García ◽  
E. Govea-Alcaide
Keyword(s):  
Barium Hexaferrite ◽  
Experimental Results ◽  
Magnetic Study ◽  
Ceramic Samples

DETERMINATION OF TRANSFER FUNCTIONS OF MCP-200 ALLOY USING 6 MV PHOTON BEAM FOR BEAM INTENSITY MODULATION

2004 ◽  
Vol 04 (03) ◽  
pp. 305-310 ◽  
Author(s):  
MUHAMMAD MAQBOOL
Keyword(s):  
Linear Accelerator ◽  
Transfer Functions ◽  
Theoretical Data ◽  
Intensity Modulation ◽  
Beam Intensity ◽  
Experimental Results ◽  
Photon Beam ◽  
Photographic Film ◽  
Optimum Dose

Transfer functions of MCP-200 alloy were determined for beam intensity modulation. 6 MV Photon beam, obtained from linear accelerator, is attenuated by blocks of MCP-200 alloy with different thicknesses placed at a distance of one meter from the source. The attenuated beam was allowed to fall on photographic film and optical densities were measured. Films were scanned and profiles were obtained for different thicknesses of the alloy and in the absence of any attenuator. Transfer functions were obtained theoretically as well as analytically by fitting the experimental results into theoretical data. The whole work was completed using optimum dose units and found to be 30 cGy.

The Characteristics of a Statically Loaded Journal Bearing with Superlaminar Flow

1980 ◽  
Vol 22 (2) ◽  
pp. 79-94 ◽  
Author(s):  
R. E. Hinton ◽  
J. B. Roberts
Keyword(s):  
Friction Factor ◽  
Journal Bearing ◽  
Load Capacity ◽  
Reynolds Numbers ◽  
Diameter Ratio ◽  
Experimental Results ◽  
Empirical Theory ◽  
Clearance Ratio ◽  
Friction Factors ◽  
Theoretical Predictions

Experimental results are presented, relating to the friction factor, load capacity and attitude angle, for a plain, cylindrical journal bearing with a central, circumferential inlet groove. The length to diameter ratio of the journal bearing was 1/3 and the clearance ratio was 0.011. By the use of various lubricants, including water, Reynolds numbers ranging from 40 to 50 000 were attained. Comparisons with various theoretical predictions are given. It is shown that a simple, empirical theory, which incorporates measured friction factors, gives better agreement with the experimental load capacity results than previous theories.

In—Line Measurement Of High Temperature Dielectric Constant In The Process Of Sintering

1996 ◽  
Vol 430 ◽  
Author(s):  
Zhou Jian ◽  
Cheng Jiping ◽  
Tang Yuling ◽  
Qiu Jinyu
Keyword(s):  
Dielectric Constant ◽  
High Temperature ◽  
Resonant Cavity ◽  
Ceramic Materials ◽  
Dielectric Constants ◽  
Experimental Results ◽  
Cavity Method ◽  
Experimental Basis ◽  
Ceramic Samples ◽  
Line Measurement

AbstractIn this paper, a resonant cavity method is developed and some experimental results for measuring dielectric constants of ceramic samples (e. g. Al2O3) under different sintering temperatures are reported. The experiments show that this method has higher precision and good prospects of in—line monitoring the high temperature dielectric constant in the process of raising the temperature of the samples. These results provide some scientific experimental basis for physical research of ceramic materials.

An Entrance Region Friction Factor Model Applied to Annular Seal Analysis: Theory Versus Experiment for Smooth and Honeycomb Seals

1989 ◽  
Vol 111 (2) ◽  
pp. 337-343 ◽  
Author(s):  
D. Elrod ◽  
C. Nelson ◽  
D. Childs
Keyword(s):  
Friction Factor ◽  
Factor Model ◽  
Experimental Results ◽  
Entrance Region ◽  
Analysis Theory ◽  
Annular Seal ◽  
Theory Versus ◽  
Direct Stiffness ◽  
Honeycomb Seals

A friction factor model is developed for the entrance-region of a duct. The model is used in an annular gas seal analysis similar to Nelson’s (1984). Predictions of the analysis are compared to experimental results for a smooth-stator/smooth-rotor seal and three honeycomb-stator/smooth-rotor seals. The model predicts leakage and direct damping well. The model overpredicts the dependence of cross-coupled stiffness on fluid prerotation. The model predicts direct stiffness poorly.

Finite Element Simulation of Cutting Forces in Turning Ti6Al4V Using DEFORM 3D

2013 ◽  
Author(s):  
Kosaraju Satyanarayana ◽  
Anne Venu Gopal ◽  
Popuri Bangaru Babu
Keyword(s):  
Heat Transfer ◽  
Finite Element ◽  
Heat Transfer Coefficient ◽  
Transfer Coefficient ◽  
Friction Factor ◽  
Cutting Forces ◽  
Experimental Results ◽  
Shear Friction ◽  
Shear Friction Factor ◽  
Deform 3D

Titanium alloys are widely used in aerospace industry due to their excellent mechanical properties though they are classified as difficult to machine materials. As the experimental tests are costly and time demanding, metal cutting modeling provides an alternative way for better understanding of machining processes under different cutting conditions. In the present work, a finite element modeling software, DEFORM 3D has been used to simulate the machining of titanium alloy Ti6Al4V to predict the cutting forces. Experiments were conducted on a precision lathe machine using Ti6Al4V as workpiece material and TiAlN coated inserts as cutting tool. L9 orthogonal array based on design of experiments was used to evaluate the effect of process parameters such as cutting speed and feed with a constant depth of cut 0.25 mm and also the tool geometry such as rake angle on cutting force and temperature. These results were then used for estimation of heat transfer coefficient and shear friction factor constant, which are used as boundary conditions in the process of simulation. Upon simulations a relative error of maximum 9.07% was observed when compared with experimental results. A methodology was adopted to standardize these constants for a given process by taking average values of shear friction factor and heat transfer coefficient, which are used for further simulations within the range of parameters used during experimentation. A maximum error of 9.94% was observed when these simulation results are compared with that of experimental results.

Delta Winglet Pairs in the Core of a Pipe and its Effect on Heat Transfer and Flow

2019 ◽  
Author(s):  
Md. Islam ◽  
Z. Chong ◽  
Md. Alam
Keyword(s):  
Heat Transfer ◽  
Pressure Drop ◽  
Friction Factor ◽  
Flow Behavior ◽  
Experimental Results ◽  
Vortex Generators ◽  
Experimental Investigations ◽  
Longitudinal Vortices ◽  
The Core ◽  
Delta Winglet

Abstract Vortex generators/turbulent promoters generate the longitudinal vortices which introduce the better mixing of the fluid with fluid circulation and enhance heat transfer. In this research, experimental investigations have been carried out to study the effect of delta winglet vortex generator (DWVG) in the core of the pipe on heat transfer and flow behavior. In this experiment, two pairs of delta winglet vortex generators (DWVG) were printed on the upside and downside of the thin plate using 3D printing technology in a ring and then placed in the core of the pipe to generate longitudinal vortices. Middle plate was very thin. The effect of heights (H = 5mm, 10mm, 15mm and 20mm) of DWVG for 10° angle of attack and 15mm spacing between leading edges of VG pairs on heat transfer and pressure drop was studied. The experiments were conducted for a fully developed turbulent flow of air in the range of Reynolds numbers (Re) 5000–25000. The influence of the DWVGs on heat transfer and pressure drop was investigated in terms of the Nusselt number (Nu) and friction factor (f). The experimental results indicate that DWVG in the core of the tube results in a considerable increase in Nu with some pressure penalty. It is found that DWVG increase Nu considerably only when H is over 10mm. Nu increases with Re and H. Friction factor decreases with Re but increase with H. The thermal performance enhancement (TPE) was noticed decreasing with Re. TPE could be obtain up to 1 only when the height is over 10mm for Re ≤ 7500. The experimental results show that the DWVG in the core of the pipe is not a good option to enhance the heat transfer at a higher Re.

Sign in / Sign up

Export Citation Format

Share Document