Radius Of Revolution Research Articles

Investigation of Machining Different Nominal Thread Diameters with the Same Thread Mill Tool Due to Varying Revolution Radius of Helical Interpolation Motion

Investigation of Machining Different Nominal Thread Diameters with the Same Thread Mill Tool Due to Varying Revolution Radius of Helical Interpolation Motion

Estimation of mean shear rate in a vessel of a planetary centrifugal mixer based on the heat balance equation

A planetary centrifugal mixer can fluidize highly viscous fluids in a vessel by strong centrifugal force. Although high rotation and revolution speeds are effective for particle dispersion, experimental observation and numerical simulation of the fluid flow in a moving vessel with a gas-liquid interface have not been well studied. Therefore, we propose the methodology to estimate a shear rate, which dominates the particle dispersion, by the temperature measurement. We measured the fluid and gas temperatures during mixing and used the heat balance equation to estimate the viscous dissipation rate, providing the mean shear rate. As a result, the effect of the mixing conditions on the mean shear rate has been clarified. Furthermore, the ratio of centrifugal force to viscous force helps identify the viscous dominant region, where not only a considerable rotation speed of the vessel but also a large revolution radius is helpful to increase the shear rate.

Orbital motion of gold heterodimer driven by optical force of circularly polarized light and reactive drag of medium

Abstract This theoretical study explores the two-dimensional orbital motion of an optically bound heterodimer consisting of two gold nanoparticles (NPs) of different sizes, driven by circularly polarized (CP) light. Although a CP light possesses only spin angular momentum without orbital angular momentum, it can still induce orbital revolution in the plasmonic heterodimer. This phenomenon arises from the interaction between the optical force and torque generated by the CP light and the reactive drag force and torque from the surrounding medium. We calculate the optical forces acting on each NP by analyzing the Maxwell stress tensor at their surfaces, and we account for the reactive drag force using Stokes’ law. These forces are used to simulate the trajectories of the NPs through dynamic equations of motion. Our results demonstrate that, regardless of the initial conditions of the two NPs, they will become optically bound together, exhibiting rigid-body translation and rotation. Notably, the center of mass of the heterodimer undergoes an orbital revolution around a fixed point eventually. The CP light-manipulated heterodimer behaves like a boomerang, acting as a spinning rotor on a circular path. The heterodimer's orbital radius and direction of revolution are influenced by the size disparity between the two NPs. Additionally, each NP experiences spin motion, with the spin direction determined by the handedness of the CP light. The optically bound gold heterodimer functions as a light-driven microrotor, with potential applications in microfluidic channels. These findings offer valuable insights into the optomechanical manipulation of non-monodisperse NP clusters using CP light.

Percolation through voids around toroidal inclusions.

In the case of media comprised of impermeable particles, fluid flows through voids around impenetrable grains. For sufficiently low concentrations of the latter, spaces around grains join to allow transport on macroscopic scales, whereas greater impenetrable inclusion densities disrupt void networks and block macroscopic fluid flow. A critical grain concentration ρ_{c} marks the percolation transition or phase boundary separating these two regimes. With a dynamical infiltration technique in which virtual tracer particles explore void spaces, we calculate critical grain concentrations for randomly placed interpenetrating impermeable toroidal inclusions; the latter consist of surfaces of revolution with circular and square cross sections. In this manner, we study continuum percolation transitions involving nonconvex grains. As the radius of revolution increases relative to the length scale of the torus cross section, the tori develop a central hole, a topological transition accompanied by a cusp in the critical porosity fraction for percolation. With a further increase in the radius of revolution, as constituent grains become more ringlike in appearance, we find that the critical porosity fraction converges to that of high-aspect-ratio cylindrical counterparts only for randomly oriented grains.

Revolution-assisted direct writing of highly controllable spiral graphene fibers with ultrasensitive photoelectric response

Spiral graphene-based fibers have enticing advantages in high breakage elongation and stable electrical property during the tensile process, but the conventional manufacturing methods are complicated and hard to produce in large quantities. Herein, we demonstrated a facile and effective revolution-assisted direct writing strategy for controllably constructing spiral graphene fiber, with a spinneret revolving along a revolution axis in the coagulation bath. The resulting spiral graphene fiber displayed excellent mechanical and electrical stability even when stretched 20000 times at 320% elongation, as well as easily regulatable radius (0.1–3.5 mm) and pitch (1–8 mm) through changing the revolution radius (distance between spinneret and revolution axis) and the motion (horizontal movement and rotation speed) of the spinneret, respectively. Moreover, functionalized with TiO2 nanoparticles, the obtained spiral composite fiber featured a highly sensitive photoelectric response to its tiny deformation, implying a great potential for liquid micro-vibration detection. This study provides a new strategy to fabricate controllably spiral graphene-based fibers with high properties.

Prediction of surface roughness and delamination in spiral milling of CFRP laminates by SAPSO-BP neural network

Due to the anisotropy carbon fibre reinforced polymer (CFRP) materials, problems such as poor surface quality of the hole wall and delamination often occur in the traditional hole-making process. In this study, the Taguchi method was used to design a CFRP spiral-milling experiment using uncoated and diamond-coated carbide cutters. The analysis of variance and signal-to-noise ratio analysis were used to study the influence of process parameters on the surface roughness and delamination factors. Prediction models for surface roughness and delamination factors were established using improved particle-swarm neural network. The results showed that the diamond-coated milling cutters are more suitable for CFRP processing. The order of importance of the process parameters is as follows: axial-feed speed > horizontal-feed speed > spindle speed > revolution radius. The prediction model for the surface roughness and delamination factors developed in this study achieves high accuracy.

Prediction of surface roughness and delamination in spiral milling of CFRP laminates by SAPSO-BP neural network

Due to the anisotropy carbon fibre reinforced polymer (CFRP) materials, problems such as poor surface quality of the hole wall and delamination often occur in the traditional hole-making process. In this study, the Taguchi method was used to design a CFRP spiral-milling experiment using uncoated and diamond-coated carbide cutters. The analysis of variance and signal-to-noise ratio analysis were used to study the influence of process parameters on the surface roughness and delamination factors. Prediction models for surface roughness and delamination factors were established using improved particle-swarm neural network. The results showed that the diamond-coated milling cutters are more suitable for CFRP processing. The order of importance of the process parameters is as follows: axial-feed speed > horizontal-feed speed > spindle speed > revolution radius. The prediction model for the surface roughness and delamination factors developed in this study achieves high accuracy.

Thermal Effect of a Revolving Gaussian Beam on Activating Heat-Sensitive Nociceptors in Skin

We consider the problem of inducing withdrawal reflex on a test subject by exposing the subject’s skin to an electromagnetic beam. Heat-sensitive nociceptors in the skin are activated wherever the temperature is above the activation temperature. Withdrawal reflex occurs when the activated volume reaches a threshold. Previously we studied static beams with 3 types of power density distribution: Gaussian, super-Gaussian, and flat-top. We found that the flaptop is the best and the Gaussian is the worst in their performance with regard to 1) minimizing the time to withdrawal reflex, 2) minimizing the energy consumption and 3) minimizing the maximum temperature increase. The less-than-desirable performance of Gaussian beams is attributed to the uneven distribution of power density resulting in low energy efficiency: near the beam center the high power density does not contribute proportionally to increasing the activated volume; outside the beam effective radius the low power density fails to activate nociceptors. To overcome the drawbacks of Gaussian beams, in this study, we revolve a Gaussian beam around a fixed point to make the power density more uniformly distributed. We optimize the performance over two parameters: the spot size of static beam and the radius of beam revolution. We find that in comparison with a static Gaussian beam, a revolving Gaussian beam can reduce the energy consumption, and at the same time lower the maximum temperature.

Mechanochemical tuning of molecular weight distribution of styrene homopolymers as postpolymerization modification in solvent‐free solid‐state

AbstractMechanochemical degradation by planetary ball milling (PM) is used for postpolymerization modification of styrene homopolymers (PS). A complete factorial design was chosen to study the effect of radical scavengers, milling time, initial molecular weight, and revolution radius (Rp), on the shape of molecular weight distributions (MWDs) of PS. Size‐exclusion chromatography analysis shows the feasibility of fine‐tuning MWD of PS at up to 40% conversion. Distributions ranged from unimodal to bimodal in a PM with Rp = 150 mm at different stage of milling, whereas in a PM with Rp of 60.8 mm the adjustment of unimodal distributions is achieved. Initial polydispersity is more important to develop bimodal distributions when compared with initial molecular weight. Fourier transform infrared and X‐ray electron spectrometry analysis show some suppression of PS degradation and complete oxidation inhibition of macromolecular radicals with the incorporation of radical scavengers, which we considered as additional aids when adjusting the MWDs.

Theoretical study on centrifugal coupling characteristics of self-rotation and revolution of particles in hydrocyclones

Porous particles containing organic waste, such as residue hydrogenation waste catalysts and oily sludge, are important hazardous pollutants. In 2017, self-rotation and revolution of particles in hydrocyclones were first experimentally measured and numerically studied for enhancing the hydrocyclone separation function of removing coating oil on spent hydrocracking catalysts. To date, however, their mechanisms are still not clearly explained using mathematical models. Accordingly, in this study, a modified mathematical model of 3-D swirling flow field in a hydrocyclone was established based on Bloor & Ingham’s model proposed in 1987, and a non-inertial self-rotation-velocity prediction model of microspheres in the hydrocyclone was established by coupling the swirling flow field and particle motion. The flow field, microspheres revolution, microspheres self-rotation, and coupled centrifugal separation in the hydrocyclone were calculated using the aforementioned two models. Results show that, compared with Bloor & Ingham’s model proposed in 1987, fluid velocities calculated using the modified model were closer to the experimental results. In the cylindrical coordinate system, the self-rotation velocity of microspheres in the forced vortex of hydrocyclones was zero; whereas that in the quasi-free vortex decreased as the revolution radius increased; that in the boundary layer rapidly increased to above 1000 rad/s with the increase of revolution radius, which was dozens of times the revolution velocity. Where the direction of inertial microsphere self-rotation in quasi-free vortex and boundary layer was opposite to the revolution direction. Besides, it could also be concluded that the periodic-oscillation coupling centrifugal force, which was generated by the revolution and high-speed self-rotation of particles near the wall, promoted the outward migration of pollutants in pores of the particles, and the calculation equation of its oscillation period was obtained. Therefore, the hydrocyclone-removal mechanism of particle-pore pollutant was revealed.

Instabilities in the free inflation of a nonlinear hyperelastic toroidal membrane

Study on an incompressible nonlinear hyperelastic thin-walled toroidal mem- brane of circular cross-section subjected to inflation due to a uniform pressure is conducted in this work. Comparisons are made for three elastic constitutive mod- els (neo-Hookean, Mooney–Rivlin, and Ogden) and for different geometric aspect ratios (ratio of the radius of cross-section to the radius of revolution). A variational approach is used to derive the equations of equilibrium and bifurcation. An analysis of the pressure–deformation plots shows occurrence of the well-known limit point (snap through) instabilities in membrane. Calculations are performed to study the elastic buckling point to predict bifurcation of solution corresponding to loss of symmetry. Tension field theory is employed to study the wrinkling instability that, in this case, typically occurs near the inner regions of tori with large aspect ratios.

Electrically rectified piezoelectric energy harvesting induced by rotary magnetic plucking

A theoretical framework together with an experimental validation is developed for the investigation of a rotational piezoelectric energy harvester attached to the standard interface circuit for AC–DC conversion. The energy harvester consists of an electrically rectified piezoelectric cantilever beam mounted on a stationary base with a magnet attached to its free end. Energy is harvested by vibration of beam induced by non-contact rotary magnetic plucking. A theoretical model accounting for magnetic coupling and rotary plucking is developed and the phenomenon of frequency up-conversion is realized by the Fourier analysis of the impulsive-like driving force. The analytic estimate of DC harvested power is derived showing that the electric response can be imitated to the case of rectilinear harmonic force vibration whereas the multiplication of the driving frequency and the integer value closely matches the device’s fundamental resonance. As a result, it exhibits broadband frequency response due to frequency up-conversion. In addition, the prediction on the crests and troughs of ripples in the DC power frequency response is remarkably found in excellent agreement with experiment. Finally, several design guidelines are proposed. These include power enhancement by lowering the ratio of perpendicular distance of magnetics to the radius of revolution, and the reduction of ripples by requiring larger mechanical damping.

Precise revolution control in three-dimensional off-axis trapping with single Laguerre-Gaussian beam

We report the precise study of orbital angular momentum transfer from Laguerre-Gaussian (LG) beams to submicrometer-sized dielectric spheres. Stable three-dimensional off-axis trapping of the spheres was achieved and confirmed by the constant behavior of the sphere’s revolution radius against the trapping LG-beam power. By measuring the revolutions of the sphere that was trapped and revolved in mid-water, we confirmed excellent linearity between the revolution rate and the trapping light free from the hydrodynamic coupling with walls of a sample chamber. This result suggests a torque source of precise controllability, which will contribute to the study of biological molecules, nonequilibrium statistical physics, and micromachines.

B208 斜板式アキシアルピストンポンプ・モータのスリッパモデルに対する数値シミュレーション : 斜板振動の影響(OS3 フルードパワーの基礎と応用1)

Vibration of a swashplate in swashplate type axial piston pumps and motors is considered in the slipper model. The theoretical model is established in consideration of vibration of the counter surface of the slipper and the calculation is performed under unsteady mixed lubrication. The representative parameters are as follows: the supply pressure of 21 MPa, the rotational speed of 25 rps, the slipper radius of 10 mm, the revolution radius of 30 mm, and the oil viscosity of 32 mPa・s. The motion, flow rate, contact pressure, and power loss are shown and the effects of the swashplate vibration and the operating conditions on the tribological characteristics of the slipper are discussed.

Vector modeling of robotic helical milling hole movement and theoretical analysis on roughness of hole surface

To avoid the machine problems of excessive axial force, complex process flow and frequent tool changing during robotic drilling holes, a new hole-making technology (i.e., helical milling hole) was introduced for designing a new robotic helical milling hole system, which could further improve robotic hole-making ability in airplane digital assembly. After analysis on the characteristics of helical milling hole, advantages and limitations of two typical robotic helical milling hole systems were summarized. Then, vector model of helical milling hole movement was built on vector analysis method. Finally, surface roughness calculation formula was deduced according to the movement principle of helical milling hole, then the influence of main technological parameters on surface roughness was analyzed. Analysis shows that theoretical surface roughness of hole becomes poor with the increase of tool speed ratio and revolution radius. Meanwhile, the roughness decreases according to the increase of tool teeth number. The research contributes greatly to the construction of roughness prediction model in helical milling hole.

Compact type-I coil planet centrifuge for counter-current chromatography

A compact type-I coil planet centrifuge has been developed for performing counter-current chromatography. It has a revolution radius of 10 cm and a column holder height of 5 cm compared with 37 and 50 cm in the original prototype, respectively. The reduction in the revolution radius and column length permits application of higher revolution speed and more stable balancing of the rotor which leads us to learn more about its performance and the future potential of type-I coil planet centrifuge. The chromatographic performance of this apparatus was evaluated in terms of retention of the stationary phase (S(f)), peak resolution (R(s)), theoretical plate (N) and peak retention time (t(R)). The results of the experiment indicated that increasing the revolution speed slightly improved both the retention of the stationary phase and the peak resolution while the separation time is remarkably shortened to yield an excellent peak resolution at a revolution speed of 800 rpm. With a 12 ml capacity coiled column, DNP-DL-glu, DNP-beta-ala and DNP-l-ala were resolved at R(s) of 2.75 and 2.16 within 90 min at a flow rate of 0.4 ml/min. We believe that the compact type-I coil planet centrifuge has a high analytical potential.

ハイブリッド・スラスト軸受の熱流体潤滑解析（斜板式アキシアルピストンポンプ・モータに用いられるスリッパのモデリング）

A thermohydrodynamic lubrication (THL) model of hybrid (hydrodynamic/hydrostatic) thrust bearings for a slipper of swashplate type axial piston pumps and motors is developed. The generalized Reynolds equation, three-dimensional energy equation and heat-conduction equation are derived, and the physical properties (density, viscosity, speci.c heat at constant pressure, thermal conductivity and thermal expansivity) of a hydraulic oil are considered as functions of temperature and pressure. The equations are solved numerically, and the THL solutions of the slipper model are compared with the isothermal solutions and the solutions of the circular thrust pad hydrostatic bearing. The e.ects of the physical properties, the revolution radius and the slipper spin on the temperature distribution, temperature rise, clearance shape and power loss are examined for both of the THL and isothermal analyses. The physical property changes in.uence on the characteristics of the slipper model rather than the characteristics of the circular pad bearing model. The THL solutions indicate that an increase in the revolution radius causes an increase in the .lm temperature and the pad inclination.

SKH51/SM45C의 마찰용접특성에 관한 연구

The present study examined the mechanical properties of the friction welding of shaft made of SKH51 and SM45C, of which the diameter is 12mm. Friction welding was done at welding conditions of 2,000rpm, friction pressure of 104MPa, upset pressure of 134MPa, friction time of 0.5sec to 2.5sec by increasing 0.5sec, upset time of 2 seconds. Under these conditions, a tensile test, a bending test, a shear test, a hardness test and a microstructure of weld interface were studied. When the friction time was 1.0 second under the conditions, the maximum tensile strength of the friction weld observed to be 963MPa, which is 89% the tensile strength of SKH51 base metal and 101% of the tensile strength of SM45C base metal. When the friction time was 1.0 seconds under the conditions, the maximum bending strength of the friction weld happened to be 1,647MPa, which is 78% the bending strength of SKH51 base metal(2,113MPa) and 87% of the bending strength of SM45C base metal(1,889MPa). When the friction time was 1.0 seconds under conditions, the maximum shear strength of the friction weld was observed to be 755MPa, which is 92% the shear strength of SKH51 base metal and 122% of the shear strength of SM45C base metal. According to the hardness test, the hardness distribution of the weld interface varied from Hv282 to Hv327. HAZ was formed from the weld interface to 1.2mm of SKH51 and 1.6mm of SM45C. Upon examination it was found that the microstructure became finer along with increase of friction revolution radius.

Retention of the stationary phase for high‐speed countercurrent chromatography

AbstractHigh‐speed countercurrent chromatography (HSCCC) is an emerging technique for preparative purification of a wide variety of solutes. Retention of the stationary phase is a crucial variable which is used for the derivation of the column efficiency, peak resolution, and solute retention. A mathematical model was proposed to describe the influences of operation conditions (flow rate, rotation speed), physical properties (density difference, viscosity, and interfacial tension), and instrument parameters (tube diameter, revolution radius) on the retention of the stationary phase, by building on the flow behavior of the two phases in the coiled column, laminar flow or droplet flow. The model parameters, together with the critical value at which the transition between the laminar flow and droplet flow occurs, were determined by the analysis of experimental data of the retention of the stationary phase measured in this work. Furthermore, the proposed model was used to predict the literature data of retention of the stationary phase for seven HSCCC apparatuses including preparative, semi‐preparative, and analytical types, with the coiled column material of PTFE and stainless steel, and for 16 two‐phase systems with 151 data points. The agreement between the predicted and the literature data is quite good with the total absolute deviation (AAD%) of 2.96% and the maximum deviation of 12.8%. © 2007 American Institute of Chemical Engineers AIChE J, 2007

NUMERICAL SIMULATION OF A SLIPPER MODEL FOR WATER HYDRAULIC PUMPS/MOTORS IN MIXED LUBRICATION

This paper presents a time-dependent mathematical model of a hybrid (hydrostatic/hydrodynamic) thrust pad bearing as a slipper of swash-plate type axial piston pumps and motors for the use of tap water under mixed and fluid fihn lubrication condition. Effects are examined of the load eccentricity, time-lag of changes in the supply pressure and load, surface roughness, recess volume, and the revolution radius. The bearing's motion is simulated three-dimensionally, including roughness interaction and asperity contact. Solutions are obtained regarding the friction, flow rate, power loss, and stiffness. Calculations indicate that the eccentric load causes local contacts. The preceding change in the load poses a larger motion of the bearing. The hydrodynamic effect becomes marked as the revolution radius increases. As the recess volume increases, the bearing stiffness decreases.