3D Fin Research Articles

Rolling-Plowing-Extrusion of Outside 3D Integral Fins on the Stainless Steel Tube

A new method of rolling-plowing-extrusion is proposed for fabricating outside 3D integral fins on the stainless steel tube. The fabricated process of fins is divided into two stages, rolling and plowing-extrusion, at first ribs are obtained on the stainless steel tube by the rolling process, and then 3D integral fins are obtained by the plowing-extrusion process. In this study, the principle of the rolling-plowing-extrusion is briefed; rolling process and plowing-extrusion process are analyzed, respectively. Through the experiments, the effect of technical parameters on fins forming and structures is investigated; experimental results are shown that accurate matching technical parameters and plowing tool angles is the key to the fins forming and structures; further analytical results indicate that when rolling speed and plowing speed is 50r/min, rolling feed rate is 0.16 mm/r, rolling depth is approximately 0.80-1.00mm, plowing feed rate is above 2.16mm/r, plowing depth is approximately 0.25-0.45mm, the optimal fins are obtained

Compound forming technology of outside 3D integral fin of copper tubes

Using rolling-ploughing-extrusion compound processing methods, a 3D integral-fin structure on outside surface of red copper tube with diameter of 16.0 mm and wall thickness of 1.5 mm was obtained. When both rolling depth and ploughing-extrusion (P-E) depth were 0.2 mm, rotating speed was 50 r/min, feed speed was 0.16 mm/r, 3D fin structures with height of 0.25 mm were gotten. Two different fin structures were obtained in grooves formed with rolling-ploughing-extrusion compound forming technology and observed by scanning electron microscope(SEM). One is the compound structure with V-shaped groove and U-shaped groove, and the other is the single structure with V-shaped grooves. Two kinds of groove structures obtained by rolling processing and ploughing extrusion processing are restricted together by groove interval and rolling depth, and pitch and P-E depth, respectively. Based on the analysis of interaction of rolling and P-E processing, it is found from the result that the outside 3D integral-fin can be achieved by rolling-ploughing-extrusion compound processing when single V-shaped groove structures are formed by both rolling and P-E processing.

Low Temperature, Beam-Orientation-Dependent, Lattice-Plane-Independent, and Damage-Free Oxidation for Three-Dimensional Structure by Neutral Beam Oxidation

To fabricate a metal oxide semiconductor field-effect transistor (MOSFET) with a three-dimensional (3D) structure, several problems arise in the conventional thermal oxidation (TO) process, such as leakage current, shape nonuniformity, stress concentration, and the dependence of the oxidation rate on the lattice plane of Si. To overcome these problems, we propose low-temperature (<300 °C) neutral beam oxidation (NBO) as an alternative oxidation process. We found that an oxide film grown by NBO (NBO film) exhibits performance characteristics of a gate dielectric film that are as high as those of thermal oxide films in terms of the relationship between equivalent oxide thickness (EOT) and leakage current. The rate of NBO is also independent of the lattice plane of Si, while the oxidation is beam orientation dependent. Therefore, growing oxide films by NBO is advantageous, in that the method can be applied to gate dielectric films for the 3D fin structure of field-effect transistors (FinFETs) and surrounding gate transistors (SGTs).

Doping fin field-effect transistor sidewalls: Impurity dose retention in silicon due to high angle incident ion implants and the impact on device performance

The three dimensional (3D) nature of a fin field-effect transistor (FinFET) structure creates new challenges for an impurity doped region formation. For the triple gate FinFET, both top and side surfaces require high levels of dopant incorporation to minimize access resistance. In this work, we investigate the use of conventional ion implantation for the introduction of impurities in this 3D silicon structure. Specifically, we evaluate sidewall impurity dose retention at various angles of incidence. The retention of dose is determined by (i) trigonometry of the implant angle in the 3D fin system, (ii) backscattering, and (iii) material properties of the target surface. Dose retention is most sensitive to the implant angle. For a fixed implant projected range, lighter ions are more likely to be ejected from the target. Thus, heavier ions are better for dose retention. The influence of sidewall dose retention on the electrical performance of fully depleted FinFETs was investigated by means of 3D device simulation. Drive current and short channel effect control are more sensitive to dose retention on sidewalls than to dopant conformality.

Fin angle effect on turbulent heat transfer in parallel‐plate channel with flow‐inclining fins

PurposeThis paper aims to develop enhanced surfaces that possess improved heat transfer rate with moderate flow pressure‐drop.Design/methodology/approachThe characteristics of the heat transfer and flow resistance in a parallel‐plate channel with flow‐inclining fins have been numerically and experimentally studied. In the turbulent flow range, the effect of the fin angle from 0 to 23.2° in addition to three channel heights, has been investigated.FindingsThe friction factor and the Nusselt number of the experimented 3D finned ducts are both lower than those of the numerical 2D channel at the same Reynolds number. The assessment under the constraint of the same pump power consumption shows that the enhancement ratio, Num/Nu0, is in between 1.6 ∼ 3.3. Showing different priority, the fin of β=23.2° is the most profitable for the 2D channel, while the case of β=16.0° is superior to the other fin angles for thicker 3D ducts.Research limitations/implicationsFor wide flat channels the 3D fins rather than the 2D fins are profitable. The deployment of the 3D fin, which is unchangeable in the current study, should be further optimized. The fin dimension and configuration in other duct forms are also challenging subjects.Practical implicationsThe results can be referenced by those who engage in design of plate‐fin heat exchangers. Attention should be paid to the optimum fin angle for different aspect ratios of the duct.Originality/valueThe study provides a practical fulfillment of the effective enhancement of the convective heat transfer with properly designed inserts that the field synergy principle predicted.

3D solid fin model construction from 2D shapes using non-uniform rational B-spline surfaces

A computer aided design (CAD) tool has been specifically developed for rapid and easy design of solid models for surfboard and sailboard fins. This tool simplifies the lofting of advanced fin cross-sectional foils, in this instance based upon the family of standard airfoil series set by the National Advisory Committee for Aeronautics (NACA), whilst retaining a basic parametric description at each cross-section. This paper describes the way in which non-uniform rational B-spline (NURBS) surfaces are created from 2D profile splines, and are then used to generate 3D geometrical surfaces of the fins, which can be imported directly into commercial software packages for finite element stress analysis (FEA) and computational fluid dynamics (CFD). Pressure distributions, lift and drag forces are determined from a CFD flow analysis for various fins designed with this tool, and the results suggest that the incorporation of advanced foils into surfboard fins could indeed lead to increased performance over fins foiled using current standard techniques.

The establishment and analysis of fin formation model during ploughing process

Owing to the present more stringent exhaust emission regulations, it becomes increasingly significant that the 3D fins on the surface of stainless steel strip used as the metal carrier of a catalytic converter is machined to improve substantially the effectiveness of the converter. Thus in this work, the mechanism of pre-roll ploughing on the surface of stainless steel strip was studied systematically, and especially the process and conditions of 3D fin formation were analyzed. Further, the proper mathematical model was established. Based on the volume of fin ploughed out being equal to the volume of the metal extruded up by the extruding face of the tool, the relation of the fin height, the distance of interval tools and the ploughing depth has been achieved. The distance of the interval of the tools has a great effect on fin height: with the increase of the distance of interval of the tools, the fin height gradually decreases. With the increase of ploughing depth (equal to groove depth), the fin height becomes larger. The theoretical analyses basically accords with experimental results. The conversion rate of a catalytic converter using a fin metal carrier is 12–15% higher than that of a catalytic converter using a smooth metal carrier of identical volume.

Extended Surface Heat Transfer

Extended Surface Heat Transfer