Fabrication of small aspheric moulds using single point inclined axis grinding

Single point inclined axis grinding techniques, including the wheel setting, wheel–workpiece interference, error source determination and compensation approaches, were studied to fabricate small aspheric moulds of high profile accuracy. The interference of a cylindrical grinding wheel with the workpiece was analysed and the criteria for selection of wheel geometry for avoiding the interference was proposed. The grinding process was performed with compensation focused on two major error sources, wheel setting error and wheel wear. The grinding results showed that the compensation approach was efficient and the developed grinding process was capable to generate small aspheric concave surfaces on tungsten carbide material with a profile error of smaller than 200 nm in PV value after two to three compensation cycles.     

Effect of inclination on gas-fluidized beds of fine cohesive powders

Results are presented of an experimental investigation on how bed inclination affects the fluidization and sedimentation behavior of fine cohesive particles. In contrast with the expected Geldart C behavior, and due to self-agglomeration, these fine particles are uniformly fluidized by gas in a vertically oriented bed, displaying a fluid-like regime and expanding smoothly as the gas velocity is increased. When the gas flow supply to the bed is suddenly stopped, the initial sedimentation velocity of the vertically oriented bed is similar to the fluidizing gas velocity as corresponds to uniform fluidization. The main effect of inclination is to induce fluidization heterogeneity. The local gas velocity increases in the adjacent region to the upper wall at the expense of the region adjacent to the lower wall. This situation anticipates the onset of local bubbling in the region adjacent to the upper wall. Meanwhile the region adjacent to the lower wall remains in a solid-like state and does not reach the fluid-like state until values of the gas flow are applied much higher than those needed in a vertical fluidized bed. As a consequence, the expansion and fluidization uniformity of the tilted bed are hindered. If the gas supply to the inclined bed is suddenly stopped, and because of induced heterogeneity, sedimentation takes place at a decreased rate as compared with sedimentation velocity in the uniformly fluidized vertical bed.     

斜井双钩箕斗线路型式的分析

通过对几个采用不同线路布置型式的实际实施斜井的汇总，阐述了箕斗斜井轨道线路布置型式及使用的利弊分析。     

Interaction of dynamic mode-I cracks with inclined interfaces

In this paper, we report on an experimental study of the deflection/penetration behavior of dynamic mode-I cracks propagating at two different crack velocities (slower and faster) toward inclined weak interfaces of three dissimilar angles (α): 30°, 45° and 60°. A simple wedge-loading specimen configuration as proposed by Xu et al. [Xu LR, Huang YY, Rosakis AJ. Dynamic crack deflection and penetration at interface in homogenous materials: experimental studies and model predictions. J Mech Phys Solids 2003;51:461-86], made of brittle Homalite-100, is used. A modified Hopkinson bar setup is used to achieve well-controlled impact loading conditions. Dynamic photoelasticity in conjunction with high-speed photography is used to capture real-time isochromatics associated with deflected/penetrated cracks.     

Fabrication of micro pin fins on inclined V-shaped microchannel walls via laser micromilling

A laser-micromilling process was developed for fabricating micro pin fins on inclined V-shaped microchannel walls for enhanced microchannel heat sinks. A pulsed nanosecond fiber laser was utilized. The feasibility and mechanism of the formation of micro pin fins on inclined microchannel walls were investigated for a wide range of processing parameters. The effects of the laser output power, scanning speed, and line spacing on the surface morphologies and geometric sizes of the micro-pin fins were comprehensively examined, together with the material removal mechanisms. Micro pin fins with acute cone tips were readily formed on the V-shaped microchannel walls via the piling of recast layers and the downflow of re-solidified materials in the laser-ablation process. The pin-fin height exhibited an increasing trend when the scanning speed increased from 100 mm/s to 300 mm/s, and it decreased continuously when the line spacing increased from 5 μm to 20 μm. The optimal processing parameters for preparing micro pin fins on V-shaped microchannels were found to be a laser output power of 21 W, scanning speed of 100–300 mm/s, and line spacing of 2–5 μm. Moreover, the V-shaped microchannels with micro pin fins induced a 7%–538% boiling heat-transfer enhancement over their counterpart without micro pin fins.The full text can be downloaded at https://link.springer.com/article/10.1007/s40436-021-00382-x     

Analytical g-function for inclined boreholes in ground-source heat pump systems

In the design of ground-source heat pump systems, the calculation of the total length of the bore field is very important because it is responsible for the major part of the initial cost. Some technologies, like direct expansion systems and pile systems, often use inclined boreholes. Most design methods do not consider this effect and may overestimate the total length needed for a typical application. This paper gives a method for the calculation of time response factors in a form called g-function for inclined boreholes. The analytical model can be used in a parameterized optimization algorithm to design an optimum bore field. The method is a generalization of a method previously proposed for vertical boreholes. Comparison of the new g-function with tabulated values found in the literature is given, and an application for a typical design is presented as an example.     

Ethanol drop impact on an inclined moving surface

This experiment investigates the impact outcomes of ethanol drop on a moving inclined surface at the various inclined angles and moving velocities. The gravity not only can promote the instability of the expanding film at downward flow but also can stabilize the film at upward flow during the drop impact onto a stationary inclined surface. Considering the horizontal moving surface, the surface velocity excites the occurrence of splashing that is toward the opposite direction of surface movement, whereas it suppresses the splashing in the same direction of surface movement. When the inclined surface moves downward at a proper surface velocity, the impact outcomes can be changed from downward splashing to deposition, and furthermore, the direction of splashing also can be changed to upward by increasing the surface velocity. The regime of deposition will be enlarged by an appropriate surface velocity, and this tendency is more obvious with a larger inclined angle.     

Numerical predictions of natural convection with liquid fluids contained in an inclined arc-shaped enclosure

In the present paper a numerical study has been performed of the flow behavior and natural convection heat transfer characteristics of liquid fluids contained in an inclined arc-shaped enclosure. The governing equations are discretized using the finite-volume method and curvilinear coordinates. The Prandtl number (Pr) of the liquid fluids is assigned to be 4.0 and the Grashof number (Gr) is ranged within the regime 1 × 10⁵ ≦ ≦ 4 × 10⁶. On the other hand, the inclination angle (θ) of the enclosure is varied within 0° ≦ θ ≦ 360°. Of major concern are the effects of the inclination and the buoyancy force on the flow and the thermal fields, and based on the numerical data of the thermal field the local and overall Nusselt numbers are calculated. Results show that the arc-shaped enclosure for Pr = 4.0 at Gr = 4 × 10⁶ and θ = 90° exhibits the best heat transfer performance. The poor heat transfer performance for Pr = 4.0 fixed at Gr = 1 × 10⁵ and θ = 180° exhibits the arc-shaped enclosure, respectively. As the value of Grashof number is elevated from 10⁵ to 4 × 10⁶, at θ = 90°, the magnitude of Nu is elevated from 13.946 to 25.3 (81.4% increase); however, at θ = 180°, the magnitude is elevated from 11.655 to 13.475 (15.6% increase) only.     

Effect of geometric and process variables on the performance of inclined plate settlers in treating aquacultural waste

Inclined plate settlers are used in treating wastewater due to their low space requirement and high removal rates. The prediction of sedimentation efficiency of these settlers is essential for their performance evaluation. In the present study, the technique of dimensional analysis was applied to predict the sedimentation efficiency of these inclined plate settlers. The effect of various geometric parameters namely, distance between plates (w(p)), plate angle (alpha), length of plate (l(p)), plate roughness (epsilon(p)), number of plates (n(p)) and particle diameter (d(s)) on the dynamic conditions, influencing the sedimentation process was studied. From the study it was established that neither the Reynolds criterion nor the Froude criterion was singularly valid to simulate the sedimentation efficiency (E) for different values of w(p) and flow velocity (v(f)). Considering the prevalent scale effect, simulation equations were developed to predict E at different dynamic conditions. The optimum dynamic condition producing the maximum E is also discussed.