Explanation of the Influence of Inflow Air Content on the Lift of Cavitating Hydrofoils

2018 ◽  
Vol 140 (8) ◽  
Author(s):  
Eduard Amromin
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Lift Coefficient ◽  
Cavity Surface ◽  
Air Bubbles ◽  
Incoming Flow ◽  
Fluid Density ◽  
Air Content ◽  
Theoretical Results ◽  
Good Agreement

According to several known experiments, an increase of the incoming flow air content can increase the hydrofoil lift coefficient. The presented theoretical study shows that such increase is associated with the decrease of the fluid density at the cavity surface. This decrease is caused by entrainment of air bubbles to the cavity from the surrounding flow. The theoretical results based on such explanation are in a good agreement with the earlier published experimental data for NACA0015.

Rate coefficients for the reaction of OH radicals with cis-3-hexene: an experimental and theoretical study

2015 ◽  
Vol 17 (14) ◽  
pp. 8714-8722 ◽  
Author(s):  
Thaís da Silva Barbosa ◽  
Silvina Peirone ◽  
Javier A. Barrera ◽  
Juan P. A. Abrate ◽  
Silvia I. Lane ◽  
...  
Keyword(s):  
Experimental Data ◽  
Theoretical Study ◽  
Rate Coefficients ◽  
Oh Radicals ◽  
Experimental Rate ◽  
Theoretical Results ◽  
Good Agreement

Microcanonical variational rate coefficients and experimental rate coefficients for the OH addition to cis-3-hexene have been determined. Theoretical results showed a non-Arrhenius profile and good agreement with the experimental data.

scholarly journals Theoretical study of the adsorption of benzene on coinage metals

2014 ◽  
Vol 10 ◽  
pp. 1775-1784 ◽  
Author(s):  
Werner Reckien ◽  
Melanie Eggers ◽  
Thomas Bredow
Keyword(s):  
Experimental Data ◽  
Density Functional Theory ◽  
Density Functional ◽  
Theoretical Study ◽  
Dispersion Correction ◽  
Functional Theory ◽  
Coinage Metals ◽  
Adsorption Energies ◽  
Theoretical Results ◽  
Good Agreement

The adsorption of benzene on the M(111), M(100) and M(110) surfaces of the coinage metals copper (M = Cu), silver (M = Ag) and gold (M = Au) is studied on the basis of density functional theory (DFT) calculations with an empirical dispersion correction (D3). Variants of the Perdew–Burke–Ernzerhof functionals (PBE, RPBE and RevPBE) in combination with different versions of the dispersion correction (D3 and D3(BJ)) are compared. PBE-D3, PBE-D3(BJ) and RPBE-D3 give similar results which exhibit a good agreement with experimental data. RevPBE-D3 and RevPBE-D3(BJ) tend to overestimate adsorption energies. The inclusion of three-center terms (PBE-D3(ABC)) leads to a slightly better agreement with the experiment in most cases. Vertical adsorbate–substrate distances are calculated and compared to previous theoretical results. The observed trends for the surfaces and metals are consistent with the calculated adsorption energies.

Investigation of Endochronic Constitutive Equation Subject to Plastic Strain-Controlled Axial-Torsional Deformation

1986 ◽  
Vol 108 (3) ◽  
pp. 262-269 ◽  
Author(s):  
Han C. Wu ◽  
J. C. Yao ◽  
S. C. Chu
Keyword(s):  
Plastic Strain ◽  
Theoretical Study ◽  
Test System ◽  
Torsional Deformation ◽  
Endochronic Theory ◽  
Phase Path ◽  
Strain Paths ◽  
Theoretical Results ◽  
Material Test System ◽  
Good Agreement

Plastic-strain controlled test is investigated both experimentally and theoretically. The plastic-strain control is feasible by means of computer-aided material test system. Theoretical study is made by use of the modified endochronic theory in which plastic strain is employed to define intrinsic time. Three in-phase plastic-strain paths (a pure axial path, a pure torsional path and an axial-torsional in-phase path) and two out-of-phase plastic-strain paths (small and large perturbations from the axial-torsional in-phase path) are studied. It is shown that the theory and experiment have good agreement. Furthermore, both experimental and theoretical results show that strain-hardening is enhanced by out-of-phase loading.

On the Comparison Between Lubrication Theory, Including Turbulence and Inertia Forces, and Some Existing Experimental Data

1975 ◽  
Vol 97 (3) ◽  
pp. 439-448 ◽  
Author(s):  
V. N. Constantinescu ◽  
S. Galetuse ◽  
F. Kennedy
Keyword(s):  
Experimental Data ◽  
Thin Films ◽  
Reynolds Numbers ◽  
Lubrication Theory ◽  
Incoming Flow ◽  
Flow Conditions ◽  
Film Rupture ◽  
Inertia Forces ◽  
Proper Consideration ◽  
Good Agreement

The results obtained by using lubrication theory, including inertia forces, are checked against experimental data concerning flows in relatively thin films at moderate and large Reynolds numbers. It is shown that a reasonably good agreement is obtained provided that the peculiar features of the experimental flow are properly taken into account; namely, proper consideration of the type of flow (laminar, transition, turbulent), proper evaluation of the region where lubrication flow prevails, entrance flow conditions (relating the flow into the film to the incoming flow), conditions for film rupture, cavitation or separation.

In-Plane Vibrations of Thick Circular Rings With T or I Cross Sections

1979 ◽  
Vol 46 (2) ◽  
pp. 470-472
Author(s):  
H. Lecoanet ◽  
J. Piranda
Keyword(s):  
Experimental Data ◽  
Eigenvalue Problem ◽  
Cross Section ◽  
Cross Sections ◽  
Rectangular Cross Section ◽  
Circular Rings ◽  
Theoretical Results ◽  
Good Agreement

This paper deals with the problem of eigenfrequencies and eigenvectors for rings whose cross section may be decomposed in basic rectangular cross sections. The solution is derived from a solution of the in-plane eigenvalue problem for rectangular cross-section thick rings. A good agreement between theoretical results and experimental data is obtained.

Analysis of Thermal Effects in Hydrodynamic Bearings

1986 ◽  
Vol 108 (2) ◽  
pp. 219-224 ◽  
Author(s):  
R. Boncompain ◽  
M. Fillon ◽  
J. Frene
Keyword(s):  
Heat Transfer ◽  
Experimental Data ◽  
Thermal Effects ◽  
Reynolds Equation ◽  
Energy Equation ◽  
Heat Transfer Equation ◽  
Reversed Flow ◽  
Theoretical Results ◽  
Generalized Reynolds Equation ◽  
Good Agreement

A general THD theory and a comparison between theoretical and experimental results are presented. The generalized Reynolds equation, the energy equation in the film, and the heat transfer equation in the bush and the shaft are solved simultaneously. The cavitation in the film, the lubricant recirculation, and the reversed flow at the inlet are taken into account. In addition, the thermoelastic deformations are also calculated in order to define the film thickness. Good agreement is found between experimental data and theoretical results which include thermoelastic displacements of both the shaft and the bush.

Thermal Behavior and Friction in Journal Bearings

1970 ◽  
Vol 92 (3) ◽  
pp. 373-380 ◽  
Author(s):  
Al. Nica
Keyword(s):  
Experimental Data ◽  
Thermal Behavior ◽  
Heat Dissipation ◽  
Journal Bearings ◽  
Friction Torque ◽  
Operating Characteristics ◽  
Lubricant Flow ◽  
Theoretical Predictions ◽  
Theoretical Results ◽  
Good Agreement

This paper deals with friction and the field of temperature in the lubricant film of journal bearings. Theoretical results regarding the thermal behavior are checked with experimental data and good agreement is found. Emphasis is put on the variation of temperature and lubricant flow with the operating characteristics of the bearing and it is seen that theoretical predictions for minima of friction torque are backed by temperature measurements. Further on, the friction torque and the mechanism of heat dissipation in bearings are dealt with, in order to verify the assumptions used in the calculation schemes. The means of efficiently cooling the bearing are also discussed, as well as the part played by the divergent zone in this process.

scholarly journals Added Mass and Damping of a Vibrating Rod in Confined Viscous Fluids

1976 ◽  
Vol 43 (2) ◽  
pp. 325-329 ◽  
Author(s):  
S. S. Chen ◽  
M. W. Wambsganss ◽  
J. A. Jendrzejczyk
Keyword(s):  
Experimental Data ◽  
Experimental Study ◽  
Cylindrical Shell ◽  
Closed Form Solution ◽  
Added Mass ◽  
Form Solution ◽  
Viscous Fluids ◽  
Series Of Experiments ◽  
Theoretical Results ◽  
Good Agreement

This paper presents an analytical and experimental study of a cylindrical rod vibrating in a viscous fluid enclosed by a rigid, concentric cylindrical shell. A closed-form solution for the added mass and damping coefficient is obtained and a series of experiments with cantilevered rods vibrating in various viscous fluids is performed. Experimental data and theoretical results are in good agreement.

Influence of the Profile Radius of the Deforming Roller on the Limit Degree of Deformation in the Process of Flow Forming

2019 ◽  
Vol 946 ◽  
pp. 800-806
Author(s):  
Andrey A. Udalov ◽  
Aleksander V. Udalov ◽  
Sergey V. Parshin
Keyword(s):  
Experimental Data ◽  
Theoretical Investigation ◽  
Theoretical Study ◽  
Initial Thickness ◽  
Flow Forming ◽  
Degree Of Deformation ◽  
Engineering Technique ◽  
Good Agreement

A theoretical investigation of the influence of the profile radius of the deforming roller on the limiting degrees of deformation in the process of flow forming is performed. Analytical and graphical dependencies allowing to determine the limiting degrees of deformation are obtained depending on the ratio of the profile radius of the roller to the initial thickness of the workpiece wall. The main practical ways of using the obtained dependences are considered. The results of the theoretical study are in good agreement with the known experimental data. The developed engineering technique can be used in designing the process of flow forming of cylindrical blanks by a torus roller.

Non-Destructive Electrical Techniques as Means for Understanding the Basic Mechanisms of Electromigration

1994 ◽  
Vol 337 ◽  
Author(s):  
A. Scorzoni ◽  
I. De Munari ◽  
H. Stulens
Keyword(s):  
Experimental Data ◽  
High Resolution ◽  
Mechanical Stress ◽  
Diffusion Model ◽  
Physical Mechanism ◽  
Relative Resistance ◽  
Resistance Change ◽  
Non Destructive ◽  
Theoretical Results ◽  
Good Agreement

ABSTRACTIn this paper results of recently developed high resolution resistometric electromigration techniques will be described, with particular attention to the behaviour of narrow, near-bamboo metal lines. After a discussion on recent theoretical results published in the literature, a diffusion model correlating mechanical stress and electromigration will be adopted to describe experimental results of relative resistance change both during and after electromigration. The good agreement between experimental data and simulations must not hide that something must still be understood about the physical mechanism leading to resistance changes during electromigration experiments.

Sign in / Sign up

Export Citation Format

Share Document