Various Angles Of Inclination Research Articles

3차원 정육면체 캐비티내 자연대류 유동 특성에 관한 수치해석적 연구

Natural convection flows in a cubical air-filled cavity that has one pair of opposing faces isothermal at different temperatures, , respectively, the remaining four faces having a linear variation from are numerically simulated by a solution code(PowerCFD) using unstructured cell-centered method. Special attention is paid to three-dimensional flow and thermal characteristics according to the variation of inclination angle of the isothermal faces from horizontal: namely $\theta

2P1-B18 上半身駆動型準受動歩行ロボットによる可変傾斜登坂実験

2P1-B18 上半身駆動型準受動歩行ロボットによる可変傾斜登坂実験

20911 上半身駆動型準受動歩行ロボットの登坂歩行における傾斜角の変化への対応(ロボティクス(3):歩行ロボットの開発,OS12 ロボティクス)

We designed and developed a quasi-passive dynamic walking robot with swinging torso, and we confirmed it can climb up a slope in a certain condition from some experiments. First, we made the strategy of climbing up slope of variable inclination angle. Next, we verified the validity of the strategy by experiments. Finally, we discussed on the treatment of contiguous/noncontiguous change of inclination angle.

Colors of Classical T Tauri Stars in Taurus Derived from Spitzer Infrared Spectrograph Spectra: Indication of Dust Settling

We analyzed Spitzer Infrared Spectrograph data of a representative sample of classical T Tauri stars in the Taurus star-forming region by computing color indices in wave bands that characterize the continuum emission from dust in circumstellar disks. We compared these indices to those derived from a grid of accretion disk models with varying inclination angles, mass accretion rates, and amounts of dust settling. We conclude that most T Tauri stars in our sample have experienced some degree of dust settling and grain growth in their disks, indicating disk evolution.

Inductively Modeling Parallel, Normal, and Frictional Forces

This year, instead of resolving the weight mg of an object resting on an incline into force components parallel and perpendicular to the surface of the incline, I asked my students to actually measure these forces at various angles of inclination and graph the data. I wanted my students to inductively discover mg sin θ and mg cos θ, and to use these graphs to confront the passive nature of the static frictional force.1 I believe the graphs themselves are very powerful conceptual tools that are often never discovered and used by students who only learn to use equations at specific angles to solve specific quantitative problems.

Method of Moments Analysis of Waveguide Slot Antennas using the EFIE

Slotted waveguide array is analyzed using the Galerkin's method of moments (MoM) with the electric field integral equation (EFIE) applied to the metallic surfaces of the waveguide structure. The approach differs from existing methods that utilizes asymptotic method, MoM with the magnetic field integral equation (MFIE), or hybrid methods of MoM and boundary element method. Since no ideal assumptions are made, the analysis and computation are considered to be theoretically and numerically rigorous. The method is verified for its accuracy and applicability through comparisons of its numerical results with existing data. New results for arrays with narrow-wall slots cut at various angles of inclination are obtained and discussed.

Proximal humeral anatomy in shoulder arthroplasty: Implications for prosthetic design and surgical technique

Resurfacing arthroplasty of the glenohumeral joint has been established for several decades as a means to restore comfort and function of the shoulder for many afflictions that derange the normal anatomy. Rigorous study of shoulder anatomy in terms relevant to prosthetic geometry, however, did not begin until the 1990s. It has become apparent that normal anatomy is highly variable from individual to individual and that it is aligned somewhat differently than the early modular prosthetic devices. Multiple studies have shown that retroversion is markedly variable, not only between individuals but also between the left and right sides of the same individual, ranging from 0 degrees to 55 degrees . The inclination of the proximal humeral articular surface relative to the shaft (head shaft angle) is also variable, ranging from 30 degrees to 55 degrees. The center of rotation is variably offset in 3 dimensions. The radius of curvature ranges from 20 to 30 mm and is smaller in women than in men. The thickness of the articular surface, head height, is equally variable but shows a striking proportionality to the radius of curvature. The last decade has seen a proliferation of humeral implants aiming to serve a better understanding of shoulder anatomy and function. A modern understanding of shoulder anatomy and contemporary design features is paramount for surgeons performing shoulder arthroplasty. Head size selection is dependent on multiple factors, the most important of these, other than the patient's original head size, are the osteotomy performed by the surgeon and the inclination angle(s) of the prosthetic system. Systems with variable inclination angles instruct the surgeon to resect the humeral head along the anatomic neck as best possible and then provide either adjustable or variable prosthetic geometries to match the resultant inclination angle. Other prosthetic systems have a fixed inclination angle somewhere within the normal range and instruct the surgeon to make an osteotomy at this inclination, adjusting the fit with additional preparation of the canal and revising the osteotomy as necessary. Over the last decade, most systems have offered heads that are offset by 3 to 4 mm, allowing the surgeon to dial in the most suitable position for the head on the stem. Component design and surgical technique are inextricably intertwined. Most surgeons with experience using modern systems feel a greater sense of predictability in achieving their surgical goals when using these systems as compared with earlier ones. How these developments impact implant longevity will only be known with time and further follow-up.

The Rotation Curves of Dwarf Galaxies: A Problem for Cold Dark Matter?

We address the issue of accuracy in recovering density profiles from observations of rotation curves of galaxies. We observe and analyze our models in much the same way as observers do the real galaxies. Our models include stellar disks, disks with bars, and small bulges. We find that the tilted-ring model analysis produces an underestimate of the central rotational velocity. In some cases the galaxy halo density profile seems to have a flat core, while in reality it does not. We identify three effects that explain the systematic biases: inclination, small bulge, and bar. Inclination effects are due to the finite thickness of the disk, bar, or bulge. Admixture of a nonrotating bulge component reduces the rotational velocity. A small (200-500 pc) bulge may be overlooked, leading to systematic bias even on relatively large (~1 kpc) distances. In the case of a disk with a bar, the underestimate of the circular velocity is larger because of a combination of noncircular motions and random velocities. The effect of the bar depends on the angle that the bar makes with the line of sight. Signatures of bars can be difficult to detect in the surface brightness profiles of the model galaxies. The variations of inclination angle and isophote position angle with radius are more reliable indicators of bar presence than the surface brightness profiles. The systematic biases in the central ~1 kpc of galaxies are not large. Each effect separately gives typically a few km s-1 error, but the effects add up. In some cases the error in circular velocity was a factor of 2, but typically we get about a 20% effect. The result is the false inference that the density profile of the halo flattens in the central parts. Our observations of real galaxies show that for a large fraction of galaxies the velocity of gas rotation (as measured by emission lines) is very close to the rotation of the stellar component (as measured by absorption lines). This implies that the systematic effects discussed in this paper are also applicable both for the stars and emission-line gas.

NUMERICAL STUDY OF LAMINAR NATURAL CONVECTION IN INCLINED RECTANGULAR ENCLOSURES OF VARIOUS ASPECT RATIOS

Numerical investigations are conducted for free convective laminar flow of a fluid with or without internal heat generation in rectangular enclosures of different aspect ratios and at various angles of inclination. Two principal parameters for this problem are the external Rayleigh number, Ra E , which represents the effect due to the differential heating of the side walls, and the internal Rayleigh number, Ra I , which represents the strength of the internal heat generation. Results are obtained for a fixed external Rayleigh number, Ra E =2 2 10 5 , with internal Rayleigh number, Ra I =0 (without internal heat generation), and also with Ra I =2 2 10 5 (with internal heat generation). Flow patterns and isotherms do not show any significant difference between the cases with and without internal heat generation other than slight shift and changes in stream function and isotherm values as long as the internal Rayleigh number Ra I is less than or equal to the external Rayleigh number Ra E . Local heat flux ratios along the hot and the cold walls decrease monotonically in the flow direction for a major downstream portion. At certain inclinations the local heat flux ratios increase initially and then decrease. The variation of average heat flux ratio is similar for cases with and without internal heat generation, but the corresponding amount of heat transfer is higher through the hot wall and lower through the cold wall with internal heat generation. On the other hand, the convection strength increases as the enclosure shape changes from slender through square to shallow at any particular inclination, but varies mildly with inclination at a particular aspect ratio.

NUMERICAL STUDY OF TURBULENT NATURAL CONVECTION IN A SIDE-HEATED SQUARE CAVITYAT VARIOUS ANGLES OF INCLINATION

Turbulent natural convection at a moderately high Rayleigh number (4.9 2 10 10 ) in a two-dimensional side-heated square cavity at various angles of inclination is studied numerically. Initially, the performance of the low Reynolds number k - y model of Wilcox (1994) and the low Reynolds number k m l turbulence model of Lam and Bremhorst (1981), in predicting buoyancy-driven flow in a noninclined enclosure, is evaluated against experimental measurements. The evaluation is focused on the prediction of the flow patterns and convective heat transfer in the boundary layer and corner regions. The performance of the Wilcox k m y model is found to be superior in capturing the flow physics such as the strong streamline curvature in the corner regions. The Lam and Bremhorst k m l model is not capable of predicting these features but provides reasonable predictions away from the corners. None of these models, however, is capable of predicting the boundary-layer transition from laminar to turbulent. In order to study the effect of the inclination of the square cavity on the heat transfer and flow patterns, computations are then performed using the Wilcox k m y model for a range of inclination angles from 0° through 90°, keeping other parameters fixed. The computed flow patterns, isotherms, convection strengths, variation of the local Nusselt numbers along the heated walls, and the average Nusselt number for various inclination angles of the square cavity are reported. It is noticed that the flow fields and heat transfer characteristics become significantly different for inclinations greater than45°. The computational procedure is based on finite-volume collocated mesh. The pressure-velocity coupling in the governing equations is achieved using the well-known SIMPLE method for numerical computation. The linear algebraic system of equations is solved sequentially using the strongly implicit procedure (SIP).

ボールエンドミル切削における切りくず生成状態と切削抵抗の予測 第１報 球体部の切れ刃形状と切削模型

Cutting edge of a sphere portion (end cutting edge) of the ball end mills is treated as the intersection of a spherical surface and a rake face approximated by a plane surface. The cutting edge configuration is geometrically analyzed, and variation of inclination angle and normal rake angle along the cutting edge is discussed. In addition, it is assumed that the line elements along the curved cutting edge of the sphere portion do not undergo extension or contraction, and the modified condition of side-curl of the chip is introduced. Then a cutting model and energy method developed for the drilling process is extended to the milling process. Expressions such as area of the shear plane and projected area of the cutting cross-section on the rake face are derived for slot milling. From the analytical results obtained through energy method, it is found that the center of side-curl of the chip is fixed near the top of the sphere portion of ball end mills and the chip is produced under this restricted condition. Furthermore, predicted result shows that Stabler's chip flow rule does not hold for the milling with ball end mills.

Lapping of Single Crystal Diamond Tools

Lapping is the key technology used in manufacturing process of diamond tools and diamond Jewels. Because of the strong anisotropism and super hardness of diamond, the material removal rate is very small in its lapping process. The Influence of the crystal anisotropism on removal rate in diamond lapping is discussed in this paper. A new diamond crystal orientation method by using laser diffraction is presented, which can not only be used for the crystal orientation, but also for the indication of ‘soft’ directions on crystal planes in lapping. The mechanism of removal rate anisotropism in diamond lapping is investigated, and a new explanation for the reasons is proposed. It is pointed out that the variation of inclination angle between Inside (111) plane (cleavage plane) and lapping surface causes the difference of friction coefficient and removal rate in diamond lapping. Furthermore, a new method using ultrasonic vibration for diamond lapping was developed to improve the removal rate.

Orientation Effects on Critical Heat Flux due to Flooding in Thin Rectangular Channel

Forced convective critical heat flux (CHF) in a rectangular channel that depended on an inclination angle was investigated. The experiment has been performed with a one side-heated thin rectangular channel under the atmospheric pressure with the inclination angle varying from 10° to 90° and mass flux from 0 to 400 kg/m2·s. The CHF was found to decrease with the inclination angle remarkably at low mass flux. Flooding CHF analysis was carried out based on the result of flow visualization in the channel, and the incorporation of inclination angle into a model was proposed. A comparison of the model prediction with experimental results showed good agreement between the measured and predicted CHF with varying inclination angle. The model was combined with a conventional CHF correlation for evaluation of mass flux, and finally a forced convective CHF correlation for an inclined thin rectangular channel was proposed.

A methodology for investigating the effect of a south oriented surface on natural illuminance received on north oriented glazing of a top lighting system under clear sky conditions

A methodology for investigating the effect of a south oriented surface with varying inclination angle in reflecting natural light towards a north oriented glazing of a top lighting system is proposed for use under clear sky conditions. This was done based on mathematical simulation for a top lighting system. Results have shown the importance of the reflective surface in increasing the illuminance received on the glazing of the top lighting system.

Orientation Effects on Critical Heat Flux due to Flooding in Thin Rectangular Channel.

Forced convective critical heat flux (CHF) in a rectangular channel that depended on an inclination angle was investigated. The experiment has been performed with a one side-heated thin rectangular channel under the atmospheric pressure with the inclination angle varying from 10° to 90° and mass flux from 0 to 400 kg/m2·s. The CHF was found to decrease with the inclination angle remarkably at low mass flux. Flooding CHF analysis was carried out based on the result of flow visualization in the channel, and the incorporation of inclination angle into a model was proposed. A comparison of the model prediction with experimental results showed good agreement between the measured and predicted CHF with varying inclination angle. The model was combined with a conventional CHF correlation for evaluation of mass flux, and finally a forced convective CHF correlation for an inclined thin rectangular channel was proposed.

Influence of experimental parameters on the erosive–corrosive wear of Al–SiC particle composite

The performance of an Al-alloy-based composite reinforced with 10 wt.% SiC particle in erosive–corrosive slurry environment was examined. The slurry consists of equiaxed sand particles of varying proportion (20, 40 and 60 wt.%) of size approximately 100 μm and solution of water, sulphuric acid and hydrochloric acid. The specimens were placed at various angles of inclination (0°, 45° and 90°) with respect to the direction of rotation of the specimens and at different radial distances (35, 55 and 75 mm) in order to assess the effect of these parameters on erosion–corrosion characteristics of composite. It was observed that wear rates increase drastically with increasing angle of inclination, sand concentration in the slurry, and radial distance. However, it was noticed that the wear rate remains unchanged when the specimen tested in a slurry containing more than 40 wt.% sand and the same become significantly less when the specimen is placed at a radial distance less than 55 mm. Scanning electron microscopic (SEM) study confirms that wear of composite is mainly governed by the synergic effect of the two simultaneous processes: (i) erosion, corrosion and abrasion of the matrix by the slurry; and (ii) fracture and removal of the dispersoid due to particle impingement at high speed. This study also revealed that wear rate at any condition increases to a maximum and then is reduced with the distance traversed. This might be due to work hardening of the specimen surface.

Effects of gas slugs and inclination angle on the ultrafiltration flux in tubular membrane module

The permeate fluxes of an inclined gas-slugs ultrafiltration system were measured and discussed under various gas–liquid flow ratios and inclination angles. The experiments were carried out in a tubular ceramic membrane module by using dextran T500 aqueous solution as the tested solution. In the single liquid-phase ultrafiltration system or the gas–liquid two-phase ultrafiltration system with turbulent liquid flow, the variation of inclination angle affects the permeate flux slightly. In the gas–liquid two-phase ultrafiltration system with laminar liquid flow, the permeate flux is enhanced significantly as the inclination of the ultrafiltration column increases up to a certain angle. The optimal inclination angle of the ultrafiltration column is about 53° in present experimental system. The enhancement in flux is due to the combination effects of natural convection and forced convection induced by the slug flow in the inclined tubular membrane.

Spiral Incremental Forging Process for Preforming of Turbine Blades with Axis Bending Control by Varying Inclination Angle of Tool.

For suppression of remarkable bending of a blade axis caused in preforming of the turbine blades with complicated shapes using incremental forging, an effective method is proposed in which metal flow during forging is controlled by varying inclination angles of tools to a billet axis. The effect of the inclination angle of tool and the specific twisting angle on the bending of the blade axis is mainly investigated by carrying out forming tests of plasticine blades with inclined flat tools. The bending of the blade axis is reduced with an increase in the specific twisting angle. The optimum inclination angle of tool, at which the bending of the blade axis is minimized, exists and depends on the specific twisting angle. The complexly curved surface of the blade can be roughly generated using the proposed method.

Diffraction of low-energy electrons at a rippled surface

An analysis is made of a kinematic model of the scattering of low-energy electrons at a onedimensional periodic toothed structure simulating a rippled surface. Calculations of the intensity profiles of the diffraction peaks are made for periodic systems of identical symmetrical triangular teeth with a variable number of atoms on each generatrix of the tooth and various angles of inclination of the generatrices to the horizontal. The main effect observed as a result of scattering at a periodic toothed structure involves broadening or splitting of the diffraction peaks compared with the diffraction patterns from a smooth chain of atoms.

EFFECTS OF BOND NUMBERS ON INTERNAL FLOW PATTERNS OF AN INCLINED, CLOSED, TWO-PHASE THERMOSYPHON AT NORMAL OPERATING CONDITIONS

A visual study of internal flow patterns inside an inclined, closed, two-phase thermosyphon at normal operating conditions for several Bond numbers has been conducted. This article describes the effects of varying inclination angles and Bond numbers (Bo) onflow patterns, A copper thermosyphon was used. R123 was selected as the working fluid, with a vapor temperature of 30°C and a filling ratio of 50%. Flow phenomena were observed at selected inclination angles of 90° and 30° from the horizontal axis, with aspect ratios of 30 and 5. The selected external diameters were 12.0 and 28.5 mm. Flow phenomena were also recorded with a standard video camera and a still camera, and the corresponding heat transfer rates were also monitored. It was observed that the basic internal flow patterns could be classified according to the aspect ratios and the Bo as follows: At an aspect ratio of 10 and higher, the annular flow at vertical changes to slug flow in inclined positions for all values of Bo. A thin liquid film always exists in the upper part, promoting heat transfer. In this case, the ratio of heat transfer rates at peak position and those of the vertical (Q / Q90) are almost the same for all Bo. At an aspect ratio of less than 10 and a low Bo, bubbly flow at vertical changes to stratified flow at an inclined position, with bubbly flow in the lower part. Vapor slug is sometimes seen. At an aspect ratio of less than 10 and a high Bo, bubbly flow with a coagulation of bubbles at the vertical position changes to stratified flow with bubbly flow in the upper part, without any vapor slugs. Q / Q90 is comparatively higher than at lower Bo. This result may be attributed to two main factors: (1) there was an area undisturbed by bubbles in the lower part; and (2) no upward vapor slug movement was observed.