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Orbital Motion of Planets
Published in Osamu Morita, Classical Mechanics in Geophysical Fluid Dynamics, 2019
The infinitesimal area dS of an annulus of radius b and b – db is () dS=2πb|db|=π(|α|mv∞2)2cos λ/2sin 3λ/2dλ.
Riveted and Bolted Joints
Published in Harold Josephs, Ronald L. Huston, Blake’s Design of Mechanical Joints, 2018
Harold Josephs, Ronald L. Huston
An effective calculation sequence is to start with an assumed value of ρ or g, defining the washer as shown in Figure 5.7. In this manner, the solution of Eqs. (5.16) and (5.17) establishes the necessary washer dimensions and the annulus width. This, in turn, permits the calculation of the approximate compressive area and the relevant spring constants.
Arc, donut and ellipse creation
Published in Bob McFarlane, Beginning AutoCAD 2002, 2012
A donut (doughnut) is a ‘solid filled’ circle or annulus (a washer shape), the user specifying the inside and outside diameters and then selecting the donut centre point. Menu bar with Draw-Donut and: Repeat the donut command and: Note: the donut command allows repetitive entries to be made by the user, while the circle command only allows one circle to be created per command – I don't know why this is!
Thermal optimisation through multilayer convective flow of CuO- MWCNT hybrid nanofluid in a composite porous annulus
Published in International Journal of Ambient Energy, 2022
Rajeev Anandika, V. Puneeth, S. Manjunatha, Ali J. Chamkha
An annulus is the space between two concentric objects of the same shape in which a larger one surrounds a smaller one. Due to their technological uses in compact heat exchangers, nuclear reactors, thermal storage systems, gas-insulated transmission lines, etc., heat transfer in the annulus in the presence of convection plays a significant role in engineering systems. Mixed convection exists when the currents of the natural convection possess the same order of magnitude as forced flow velocities and when forced and natural convection together contribute to the heat transfer, mixed convection occurs. The contribution of each of these convection mechanisms is dependent on the flow pattern and the magnitude of the temperature driving force. In this regard, Shahsavar et al. (2021) considered eccentric annulus to analyse the effect of free convection through the first and second law of thermodynamics. Shahsavar et al. (2021) have also given the details on entropy generation for the flow of nanofluid in a horizontal annulus. Miles and Bessaih (2021) performed the analysis of entropy generation for the fluids flowing past a cylindrical annulus. Mirzaie and Lakzian (2021) discussed the effect of natural convection near the density inversion point for the nanofluid flowing in a cylindrical annulus. Abd-Allah and Alsedais (2021) studied the impact of magnetic field on the heat and mass profile of nanofluid flowing in an annulus between a cavity and an elliptical obstacle.
Dispersed-phase Volume Fraction and Flow Regimes in Oscillatory Liquid-Liquid Two-Phase Flow in Annuli: Comparison of Sieve-Plate and Baffle-Plate Internals
Published in Solvent Extraction and Ion Exchange, 2021
Sourav Sarkar, Mayur Darekar, K.K. Singh, K.T. Shenoy
The effect of continuous phase velocity on dispersed phase volume fraction is also studied for both types of internals. The continuous phase velocity is varied in the range from 0.00735 m/s to 0.0165 m/s. Continuous-phase velocity is defined as continuous phase flow rate per unit cross-sectional area of the annulus. For these experiments, the dispersed phase velocity is 0.0037 m/s. The amplitude of the oscillation is 0.0278 m and the frequency of the oscillation is 1 Hz. Thus, the oscillation velocity is 0.0278 m/s. As discussed later, the flow regime at this oscillation velocity is the dispersion regime. The outer diameter of the annulus is 0.1016 m and the inner diameter is 0.067 m (Annulus2). The open area is 25%. Baffle or sieve-plate spacing is 0.05 m. Figure 3a shows the variation of dispersed phase volume fraction with variation in continuous phase velocity for both types of internals. An enhancement in continuous phase velocity increases dispersed phase volume fraction marginally for both types of internals. With an increase in continuous phase velocity, the drag force exerted by the continuous phase on the rising drops increases. Increased drag force leads to increased retention of dispersed phase in the annulus. This leads to an increase of dispersed phase volume fraction inside the annulus. As observed in the experiments on the effect of dispersed phase velocity on dispersed phase volume fraction, the dispersed phase volume fraction is found to be more for baffle-plate internals than for sieve-plate internals for the entire range of variation of the continuous phase velocity.
Mean flow generation due to longitudinal librations of sidewalls of a rotating annulus
Published in Geophysical & Astrophysical Fluid Dynamics, 2020
Michael V. Kurgansky, Torsten Seelig, Marten Klein, Andreas Will, Uwe Harlander
In this paper we investigate the steady jet formation observed near a librating vertical wall of an annulus that, as a whole, rotates with the constant angular velocity . The annulus is shown in figure 1 and constituted by two co-axial, inner and outer, cylinders with height h = 2H and radii a and b, respectively. The annulus is closed by bottom and top lids, and , which are orthogonal to the axis of rotation and the cylindrical sidewalls. In the laboratory experiments, the aspect ratio is of order unity. The inner cylinder radius a is, as a rule, comparable by magnitude with the outer cylinder radius b. The steady flow generation effect is caused by librations of the inner cylinder, whose rotation rate is harmonically modulated as , where ω is the frequency and the amplitude of libration. The lids remain to rotate with the angular velocity . The main objective of the present work is the detailed analysis of a steady (prograde) jet near that straight cylindrical wall, which is found in the libration experiments.