scholarly journals Investigation of Additively Manufactured Wind Tunnel Models with Integrated Pressure Taps for Vortex Flow Analysis

Aerospace ◽  
2019 ◽  
Vol 6 (10) ◽  
pp. 113 ◽  
Author(s):  
Matteo Moioli ◽  
Christopher Reinbold ◽  
Kaare Sørensen ◽  
Christian Breitsamter
Keyword(s):  
Wind Tunnel ◽  
Best Practice ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Leading Edge ◽  
Tunnel Model ◽  
Manufacturing Techniques ◽  
The Cost ◽  
Swept Wings

Wind tunnel models are traditionally machined from high-quality metal material; this condition reduces the possibility to test different geometric variations or models as it corresponds to incremental cost. In the last decade, the quality of additive manufacturing techniques has been progressively increasing, while the cost has been decreasing. The utilization of 3D-printing techniques suggests the possibility to improve the cost, time, and flexibility of a wind tunnel model production. Possible disadvantages in terms of quality of the model finishing, stiffness, and geometric accuracy are investigated, to understand if the production technique is capable of providing a suitable test device. Additionally, pressure taps for steady surface pressure measurements are integrated during the printing procedure and the production of complex three-dimensional highly swept wings have been selected as targets. Computational fluid dynamics tools are exploited to confirm the experimental results in accordance with the best practice approaches characterizing flow patterns dominated by leading-edge vortices. The fidelity level of the experimental data for scientific research of the described flow fields is investigated. An insight of the most important guidelines and the possible improvements is provided as well as the main features of the approach.

scholarly journals MANUFACTURING TECHNIQUE OF METAL CERAMIC RESTORATION WITH IMPLANT-ABUTMENT AT GINGIVAL RESORPTION CASE

2019 ◽  
Vol 3 (1) ◽  
pp. 22
Author(s):  
Galih Paramarta ◽  
Eny Inayati
Keyword(s):  
Three Dimensional ◽  
Dental Restoration ◽  
Coating Application ◽  
Manufacturing Technique ◽  
Implant Abutment ◽  
Metal Ceramic ◽  
Manufacturing Techniques ◽  
The Aesthetic ◽  
Ceramic Restorations

Background: The low levels of patient satisfaction and confidence in the restoration of the gingival resorption results in impaired quality of life in both functional and psychosocial aspects. It is necessary to manufacture a dental restoration to restore the mastication, phonetic, and aesthetic functions associated with soft tissue repair. Manufacture of gingiva ceramic restorations which are believed to be an alternative to restore the aesthetic function and harmonization of the patient’s teeth. In terms of manufacturing techniques, this restoration has a level of difficulty in achieving a balance between “White aesthetic” and “aesthetic pink”. Objective: This study aims to provide knowledge to the reader of Manufacturing Technique of Metal Ceramic Restoration with Implant-Abutment at Gingival Resorption Case. Reviews: Gingiva ceramic restorations can be used to create esthetic implant-supported restorations when bone and gingival tissues are deficient and surgical replacement of such tissues is not possible. Dental technicians should be able to analyze the three-dimensional shapes of gingival anatomy, color, texture, smile components, the balance of the “pink aesthetic” and “white aesthetic”. Conclusion: Manufacturing Technique of Metal Ceramic Restoration with Implant-Abutment at Gingival Resorption Case including the manufacture of metal coping, oxidation, application of opaque coating, application of the first “white aesthetic” ceramics (Opaque Dentine, Dentine, Enamel and transpa on crown coping restorations), Application of opaque gingiva layer, gingival ceramics build-up "pink aesthetics”, first firing, followed by correction build-up, and second firing, and ends with the glazing process.

scholarly journals Numerical Simulation of Cascade Flow: Vortex Element Method for Inviscid Flow Analysis and Axial Turbine Blade Design

2021 ◽  
Vol 85 (2) ◽  
pp. 14-23
Author(s):  
Nono Suprayetno ◽  
Priyono Sutikno ◽  
Nathanael P. Tandian ◽  
Firman Hartono
Keyword(s):  
Best Practice ◽  
Lift Coefficient ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Inviscid Flow ◽  
Turbine Rotor ◽  
Design Stage ◽  
Outer Diameter ◽  
Axial Turbine ◽  
Cascade Flow

This study aims to design an axial turbine rotor blade and predict the turbine performance at preliminary design stage. Quasi three dimensional method was applied to design including blade to blade flow analysis. The blade profile uses a NACA 0015 airfoil by varying the profile thickness from hub to tip. The profile is divided into eleven segments which has different parameters. The profile was analysed using blade to blade flow/cascade flow analysis called vortex panel method to obtain lift coefficient. The analysis of cascade flow was performed in potential flow and prediction of turbine perfomance is carried out involving common best practice to give drag effect on the blade. The design of the turbine was applied on three different rotors, which also have a different discharge, head, and design rotation. The outer diameter of turbine 1 is 0.65 m, while turbine 2 and turbine 3 have an outer diameter of 0,60 m. The calculation result show that the efficiency of turbines 1, 2, and 3 were 88,32%, 89,67%, and 89,04%, respectively.

Numerical Flow Analysis in a Subsonic Vaned Radial Diffuser With Leading Edge Redesign

1999 ◽  
Vol 121 (1) ◽  
pp. 119-126 ◽  
Author(s):  
E. Casartelli ◽  
A. P. Saxer ◽  
G. Gyarmathy
Keyword(s):  
Static Pressure ◽  
Flow Analysis ◽  
Three Dimensional ◽  
Pressure Rise ◽  
Leading Edge ◽  
Inverse Design ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Characteristic Lines ◽  
Design Software

The flow field in a subsonic vaned radial diffuser of a single-stage centrifugal compressor is numerically investigated using a three-dimensional Navier–Stokes solver (TASCflow) and a two-dimensional analysis and inverse-design software package (MISES). The vane geometry is modified in the leading edge area (two-dimensional blade shaping) using MISES, without changing the diffuser throughflow characteristics. An analysis of the two-dimensional and three-dimensional effects of two redesigns on the flow in each of the diffuser subcomponents is performed in terms of static pressure recovery, total pressure loss production, and secondary flow reduction. The computed characteristic lines are compared with measurements, which confirm the improvement obtained by the leading edge redesign in terms of increased pressure rise and operating range.

Impact of Cavity on Sunroof Buffeting: A Two Dimensional CFD Study

2004 ◽  
Author(s):  
Chang-Fa An ◽  
Seyed Mehdi Alaie ◽  
Michael S. Scislowicz
Keyword(s):  
Fluid Dynamics ◽  
Wind Tunnel ◽  
Three Dimensional ◽  
Leading Edge ◽  
Two Dimensional ◽  
Deep Insight ◽  
Simulation Results ◽  
Dimensional Simulation ◽  
The Impact ◽  
Insight Into

Driven by fluid dynamics principles, the concept for buffeting reduction, a cavity installed at the leading edge of the sunroof opening, is analyzed. The cavity provides a room to hold the vortex, shed from upstream, and prevents the vortex from escaping and from directly intruding into the cabin. The concept has been verified by means of a two dimensional simulation for a production SUV using the CFD software — FLUENT. The simulation results show that the impact of the cavity is crucial to reduce buffeting. It is shown that the buffeting level may be reduced by 3 dB by adding a cavity to the sunroof configuration. Therefore, the cavity could be considered as a means of buffeting reduction, in addition to the three currently-known concepts: wind deflector, sunroof glass comfort position and cabin venting. Thorough understanding of the buffeting mechanism helps explain why and how the cavity works to reduce buffeting. Investigation of the buffeting-related physics provides a deep insight into the flow nature and, therefore, a useful hint to geometry modification for buffeting reduction. The buffeting level may be further reduced by about 4 dB or more by cutting the corners of the sunroof opening into smooth ramps, guided by ideas coming from careful examining the physics of flow. More work including three dimensional simulation and wind tunnel experiment should follow in order to develop more confidence in the functionality of the cavity to hopefully promote this idea to the level that it can be utilized in a feasible way to address sunroof buffeting.

scholarly journals Review of Powder Bed Fusion Additive Manufacturing for Metals

Metals ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1391
Author(s):  
Leila Ladani ◽  
Maryam Sadeghilaridjani
Keyword(s):  
Additive Manufacturing ◽  
Three Dimensional ◽  
Disruptive Technology ◽  
Powder Bed ◽  
Powder Particles ◽  
Metallic Parts ◽  
The Cost ◽  
Scientific Questions ◽  
Metal Additive

Additive manufacturing (AM) as a disruptive technology has received much attention in recent years. In practice, however, much effort is focused on the AM of polymers. It is comparatively more expensive and more challenging to additively manufacture metallic parts due to their high temperature, the cost of producing powders, and capital outlays for metal additive manufacturing equipment. The main technology currently used by numerous companies in the aerospace and biomedical sectors to fabricate metallic parts is powder bed technology, in which either electron or laser beams are used to melt and fuse the powder particles line by line to make a three-dimensional part. Since this technology is new and also sought by manufacturers, many scientific questions have arisen that need to be answered. This manuscript gives an introduction to the technology and common materials and applications. Furthermore, the microstructure and quality of parts made using powder bed technology for several materials that are commonly fabricated using this technology are reviewed and the effects of several process parameters investigated in the literature are examined. New advances in fabricating highly conductive metals such as copper and aluminum are discussed and potential for future improvements is explored.

scholarly journals Experimental and Computational Analysis of Model–Support Interference in Low-Speed Wind-Tunnel Testing of Fuselage-Boundary-Layer Ingestion

2019 ◽  
Vol 304 ◽  
pp. 02020
Author(s):  
Biagio Della Corte ◽  
André A.V. Perpignan ◽  
Martijn van Sluis ◽  
Arvind Gangoli Rao
Keyword(s):  
Boundary Layer ◽  
Wind Tunnel ◽  
Wind Tunnel Test ◽  
Leading Edge ◽  
Horseshoe Vortex ◽  
Junction Flow ◽  
Tunnel Model ◽  
Aerodynamic Interaction ◽  
Support Interference ◽  
Model Support

Junction flow caused by the aerodynamic interaction between a wind-tunnel model and the support structure can largely influence the flowfield and hence the experimental results. This paper discusses a combined numerical and experimental study which was carried out to mitigate the model–support interference in a wind-tunnel test setup for the study of fuselage boundary-layer ingestion. The setup featured an axisymmetric fuselage mounted through a support beam, covered by a wing-shaped fairing. The junction flow appearing at the fuselage–fairing connection produced undesired flow distortions at the fuselage aft section, due to the formation of an horseshoe vortex structure at the fairing leading edge. Numerical and experimental analysis were performed with the aim of reducing the distortion intensity by improving the fairing design. Results show that modifying the leading-edge shape of the fairing effectively decreased the flowfield distortions. Moreover, the addition of a dummy fairing diametrically opposed to the first one was found to be beneficial due to the enhancement of the configuration symmetry.

scholarly journals Pesticide Application Quality With Alternative Use of Water Sensitive Paper

2019 ◽  
Vol 11 (6) ◽  
pp. 528
Author(s):  
João Paulo Tomasini Castoldi ◽  
Diandra Ganascini ◽  
Luciene Kazue Tokura ◽  
Eduardo Lange Sutil ◽  
Soni Willian Haupenthal ◽  
...  
Keyword(s):  
Wind Tunnel ◽  
State University ◽  
Droplet Volume ◽  
Pesticide Application ◽  
Spray Droplets ◽  
Different Types ◽  
The Cost ◽  
Medium Diameter ◽  
Droplet Density

The water sensitive paper is commonly used in the uniformity and distribution ratings of the spray droplets pattern; however, this technology still has a high cost. In this way, the present work had as objective to evaluate the quality of deposition of spray drops in different types of papers sensitive to water. The test was carried out in a wind tunnel built inside the multi-sport gymnasium of the State University of West Paraná-campus of Cascavel-PR. A semi-automated nozzle transition prototype was used to perform the tests. The variables evaluated were number of diameters, dispersion, volumetric medium diameter (VMD), droplet density, cover and droplet volume. The treatments consisted of four different types of paper compared to the water sensitive paper (control), and two nozzles. Cardboard paper stood out among the others at the cost of approximately 1% of a water-sensitive paper slip. The water sensitive paper used in agriculture can be replaced by alternative papers more economically viable and easily found in the market.

scholarly journals Steel gratings as an innovative temporary roads pavement

2016 ◽  
Vol 15 (1) ◽  
pp. 105-114
Author(s):  
Artur Juszczyk ◽  
Adam Wysokowski
Keyword(s):  
New Technologies ◽  
Three Dimensional ◽  
Concrete Slabs ◽  
Local Conditions ◽  
Traditional Design ◽  
Innovative Solution ◽  
Ground Conditions ◽  
Pavement Structures ◽  
The Cost

The needs related to reduction of lead time and quality of construction determines implementation of the new technologies. An example of such an activity is a development of pavements used to build temporary roads, carried out mainly for the needs of equipment and materials delivery to a construction site. This is especially important in civil engineering, where location is dictated by a number of local conditions, which often is associated with the occurrence of adverse groundwater conditions. Commonly used traditional design solutions of temporary roads such as unpaved roads or roads made by concrete slabs require good ground conditions or proper stabilized subsoil,which may ultimately result in a significant increase of the cost of the construction. Modern temporary paving structures not only transmit the exploitation load on the subsoil. They use subsoil, as a an structure cooperating in load distribution, so it is possible to use such a construction of road on a low-bearing soil. An innovative solution in this case are three-dimensional steel grids cooperating with a subsoil. The paper describes the preliminary modeling studies of this type of pavement structures.

scholarly journals Design and Experimental Characterization of an Actuation System for Flow Control of an Internally Blown Coanda Flap

Aerospace ◽  
2020 ◽  
Vol 7 (3) ◽  
pp. 29 ◽  
Author(s):  
Peter Wierach ◽  
Jan Petersen ◽  
Michael Sinapius
Keyword(s):  
Wind Tunnel ◽  
Flow Control ◽  
Research Work ◽  
Three Dimensional ◽  
Installation Space ◽  
Commercial Aircraft ◽  
Wind Tunnel Model ◽  
Actuation System ◽  
Tunnel Model ◽  
Actuator System

The focus of the work is on the evaluation, development and integration of a robust actuator system for three-dimensional flow control of a blown Coanda flap to improve the high lift system of commercial aircraft. As part of the research work presented, the system is integrated into a wind tunnel model in order to influence the flow across the entire width of the model. The system developed is based on individual bending transducers that can vary the height of the blowing slot dynamically. The system is divided into 33 segments and is therefore able to implement static and dynamic actuation along the wing-span (3D-actuation). All segments can be controlled independently and thus offer great optimization potential for an effective flow control. Different configurations were developed and evaluated against each other with respect to the demanding requirements (small installation space, frequency range from 5 Hz to 300 Hz, 1 bar pressure, 0.4 mm deflection, 1 m span). The design of the blown flap has been specified in an iterative design process. In the final configuration, all mechanical components are reduced to the bare minimum for weight reduction reasons, in order to meet the dynamic requirements of the wind tunnel model. To characterize the lip segments, a test device has been designed that can be pressurized to generate aerodynamic loads on the lip segments. Finally, 33 lip segments were integrated into a wind tunnel model and tested intensively as part of a measurement campaign. The first aerodynamic results show an increase in lift of up to ∆Ca = 0.57. These aerodynamic gains are achieved at amplitudes that do not require the lip segments to completely close or open the blowing slot, which shows the advantage of the current lip design that enables activation with independently controlled stationary and unsteady components.

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