Effects of manufacturing parameters on performance of fluidic oscillators for aerodynamic flow control

2018 ◽  
Vol 233 (10) ◽  
pp. 3603-3611 ◽  
Author(s):  
V Jhaveri ◽  
M DeSalvo ◽  
A Glezer ◽  
J Colton
Keyword(s):  
Manufacturing Process ◽  
Oscillation Frequency ◽  
Material Selection ◽  
Selective Laser Sintering ◽  
Performance Characteristics ◽  
Inlet Pressure ◽  
Nozzle Geometry ◽  
Rate Variation ◽  
Dimensional Variation ◽  
Aerodynamic Flow Control

An investigation is conducted into the effects of dimensional variation, material selection, and manufacturing process on the performance characteristics of a self-oscillating fluidic oscillator. Measurements of oscillation frequency, inlet pressure, and jet profile are performed for actuators having varying nozzle and cavity dimensions. Actuators made of aluminum and carbon fiber reinforced polyetherketoneketone are tested, and the effects of varying manufacturing processes between machining, selective laser sintering, stereolithography, and injection molding are assessed. Models based on dimensionless variables are used to characterize the variation in frequency and inlet pressure for a given mass flow rate. Variation of the nozzle geometry and cavity shoulder width influence the oscillation frequency, and variation of nozzle geometry affects the required driving pressure. Dimensional variations due to manufacturing process tolerances are found to affect actuator performance characteristics, while material selection alone does not affect, provided manufacturing to the required tolerances is possible.

Selection of selective laser sintering materials for different applications

2015 ◽  
Vol 21 (6) ◽  
pp. 630-648 ◽  
Author(s):  
Sunil Kumar Tiwari ◽  
Sarang Pande ◽  
Sanat Agrawal ◽  
Santosh M. Bobade
Keyword(s):  
Process Parameters ◽  
High Performance ◽  
Material Selection ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Optimal Process ◽  
Content Type ◽  
Volume Production ◽  
High Performance Application ◽  
Selection Of

Purpose – The purpose of this paper is to propose and evaluate the selection of materials for the selective laser sintering (SLS) process, which is used for low-volume production in the engineering (e.g. light weight machines, architectural modelling, high performance application, manufacturing of fuel cell, etc.), medical and many others (e.g. art and hobbies, etc.) with a keen focus on meeting customer requirements. Design/methodology/approach – The work starts with understanding the optimal process parameters, an appropriate consolidation mechanism to control microstructure, and selection of appropriate materials satisfying the property requirement for specific application area that leads to optimization of materials. Findings – Fabricating the parts using optimal process parameters, appropriate consolidation mechanism and selecting the appropriate material considering the property requirement of applications can improve part characteristics, increase acceptability, sustainability, life cycle and reliability of the SLS-fabricated parts. Originality/value – The newly proposed material selection system based on properties requirement of applications has been proven, especially in cases where non-experts or student need to select SLS process materials according to the property requirement of applications. The selection of materials based on property requirement of application may be used by practitioners from not only the engineering field, medical field and many others like art and hobbies but also academics who wish to select materials of SLS process for different applications.

scholarly journals Dynamic simulation of the oscillation characteristics of supercritical carbon dioxide impacting jets

2018 ◽  
Vol 25 (1) ◽  
pp. 61-71 ◽  
Author(s):  
Xinwei Zhang ◽  
Yiyu Lu ◽  
Jiren Tang ◽  
Zhe Zhou ◽  
Qian Li
Keyword(s):  
Carbon Dioxide ◽  
Numerical Model ◽  
Supercritical Carbon Dioxide ◽  
Oscillation Frequency ◽  
High Speed ◽  
Rock Breaking ◽  
Target Distance ◽  
Inlet Pressure ◽  
Oscillation Characteristics ◽  
Supercritical Carbon

A numerical model was established to investigate the dynamic oscillation characteristics of supercritical carbon dioxide (sc-CO2) impacting jets. The jet hydrodynamics, heat transfer, and physical properties of sc-CO2 fluid were incorporated into the model. The coupling of multiple fields with large velocity and pressure gradients was achieved using a modified SIMPLE segmentation algorithm. Laboratory experiments validated the reliability of the numerical model by detecting dynamic changes in the pressure on the centerline of the sc-CO2 impacting jet. Analysis of the flow field showed single or double high-speed sc-CO2 mass structures for the sc-CO2 impacting jet, revealing the generation mechanism of the impacting oscillation frequency and the mechanism of improved rock-breaking efficiency by sc-CO2 jet. The oscillation frequency equation was obtained through a quantitative treatment of the velocity and motion area of the sc-CO2 mass. Finally, the equation and simulation results were used to analyze the influences of the target distance, inlet pressure and temperature on the sc-CO2 jet oscillation characteristics. The results showed that the oscillation frequency and amplitude first increased and then decreased with increases in the target distance. The oscillation frequency and amplitude both increased with increasing inlet pressure; the oscillation frequency increased slowly with increasing temperature.

Laser Additive Manufacturing

3D Printing ◽  
2017 ◽  
pp. 154-171 ◽  
Author(s):  
Rasheedat M. Mahamood ◽  
Esther T. Akinlabi
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Computer Aided Design ◽  
Selective Laser Sintering ◽  
Three Dimensional ◽  
Cad Model ◽  
Laser Additive Manufacturing ◽  
Computer Aided ◽  
Manufacturing Technologies ◽  
Aided Design

Laser additive manufacturing is an advanced manufacturing process for making prototypes as well as functional parts directly from the three dimensional (3D) Computer-Aided Design (CAD) model of the part and the parts are built up adding materials layer after layer, until the part is competed. Of all the additive manufacturing process, laser additive manufacturing is more favoured because of the advantages that laser offers. Laser is characterized by collimated linear beam that can be accurately controlled. This chapter brings to light, the various laser additive manufacturing technologies such as: - selective laser sintering and melting, stereolithography and laser metal deposition. Each of these laser additive manufacturing technologies are described with their merits and demerits as well as their areas of applications. Properties of some of the parts produced through these processes are also reviewed in this chapter.

Elastic Bellows Prepared by Selective Laser Sintering

2014 ◽  
Vol 630 ◽  
pp. 318-325 ◽  
Author(s):  
Czesław Kundera ◽  
Tomasz Kozior
Keyword(s):  
Internal Pressure ◽  
Elastic Properties ◽  
Axial Force ◽  
Process Parameters ◽  
Manufacturing Process ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Additive Technology ◽  
Printing Process ◽  
Measurement Results

The article contains the results of studies concerning the effects of selected parameters of the manufacturing process of elastic bellows on their elastic properties and strength. Bellows models were made using additive technology SLS selective laser sintering, in which the material used to construct models was a polyamide PA 2200. Bellows printing process proceeded in a surface parallel to the axis of the bellows and in a surface perpendicular to it. Based on measurements of deformation coefficients of elasticity of bellows were determined, also the measure of the maximum axial force exerted by the bellows while loading the internal pressure was carried out. Comparing the measurement results a significant effect of process parameters on the flexible properties of elastic bellows and their resistance to internal pressure were determined.

Assembly Tool Manufacturing and Optimization for Polylactic Acid Additive Manufacturing

2019 ◽  
Vol 952 ◽  
pp. 153-162 ◽  
Author(s):  
Šimon Lecký ◽  
Stefan Václav ◽  
Dávid Michal ◽  
Róbert Hrušecký ◽  
Peter Košťál ◽  
...  
Keyword(s):  
Additive Manufacturing ◽  
Polylactic Acid ◽  
Manufacturing Process ◽  
Material Selection ◽  
Plastic Material ◽  
Current Trend ◽  
Poly Lactic Acid ◽  
Clean Manufacturing ◽  
Measuring Machine ◽  
Assembly Tool

Paper focuses on additive manufacturing of assembly tool for hole selection. One of the most important part in design and optimization process in additive manufacturing for assembly tool is material selection and technology. In this case was chosen plastic material know as poly-lactic-acid. Polylactic acid has low shrinkage and huge potential in assembly tooling and assembly fixture manufacturing. Main benefits are in use of additive manufacturing for this purpose because of huge manufacturing variability and time savings in case of frequent design changes. From filament fused fabrication technology stand point is important to determine right manufacturing orientation of part. Main material benefit is bio-degradability and recyclability. Current trend in manufacturing is bio materials, clean manufacturing and ecofriendly products. Correct orientation of assembly tool will optimize manufacturing process in one way. Article is aimed on manufacturing precision in each orientation of part on build late. With right orientation of part in additive manufacturing process is determined exact precision of assembly tool manufacturing. For measurement was used coordinate-measuring machine. In this case measurements and precision checking are made only in exact spots where is needed the most precise distance

scholarly journals Ablative Laser Structuring for Stretchable Multilayer and Multi-Material Electronics and Sensor Systems

Proceedings ◽  
2020 ◽  
Vol 56 (1) ◽  
pp. 21
Author(s):  
Simon P. Stier ◽  
Holger Böse
Keyword(s):  
Additive Manufacturing ◽  
Manufacturing Process ◽  
Fused Deposition Modeling ◽  
Selective Laser Sintering ◽  
Circuit Board ◽  
Circuit Boards ◽  
Thermoplastic Polymers ◽  
Digital Light Processing ◽  
Fused Deposition ◽  
Liquid Silicone

Conventional machining and shaping processes for polymers and elastomers such as injection molding exhibit significant disadvantages, as specific tools have to be manufactured, the method of machining is highly dependent on the material properties, and the cost of automation is usually high. Therefore, additive manufacturing processes (3D printing) have established themselves as an alternative. This eliminates the expensive production of tools and the production is individualized. However, the specific (additive) manufacturing process remains highly dependent on the properties of the material. These processes include selective laser sintering (SLS) for powdered thermoplastic polymers and metals, extrusion such as fused deposition modeling (FDM) for thermoplastic polymers in wire form, or optical curing such as digital light processing (DLP) for liquid resins. Especially for elastomer sensors or circuit boards (structure of several alternately constituted approx. 100 µm-thick elastomer films made with different types of liquid silicone rubber), there is no suitable additive manufacturing process that combines liquid, partly non-transparent source materials, multi-component printing, and very fine layer thicknesses. In order to enable a largely automated, computer-aided manufacturing process, we have developed the concept of ablative multilayer and multi-material laser-assisted manufacturing. Here, the layers (conductive and non-conductive elastomers, as well as metal layers for contacting) are first coated over the entire surface (e.g., spray, dip, or doctor blade coating, as well as galvanic coating) and then selectively removed with a CO2 or fiber laser. These steps are repeated several times to achieve a multi-layer structured design. Is it not only possible to adjust and improve the work previously carried out manually, but also to introduce completely new concepts, such as fine through-plating between the layers to enable much more compact structures to be possible. As an exemplary application, we have used the process for manufacturing a thin and surface solderable pressure sensor and a stretchable circuit board.

SLS unter die Lupe genommen*/SLS under the microscope – An evaluation of the accuracy of selective laser sintering processes

2015 ◽  
Vol 105 (01-02) ◽  
pp. 72-77
Author(s):  
M. Fleßner ◽  
B. Galovskyi ◽  
T. Hausotte ◽  
A. Loderer
Keyword(s):  
Optimal Design ◽  
Measurement System ◽  
Manufacturing Process ◽  
Selective Laser Sintering ◽  
Laser Sintering ◽  
Manufacturing Processes ◽  
Wird Eine ◽  
Sintering Process ◽  
Batch Sizes ◽  
Sintering Processes

Generative Fertigungsverfahren erlauben die wirtschaftliche Fertigung auch kleiner Losgrößen. Um diesen Vorteil durch eine gute Qualität zu sichern, wird eine Messtechnik entwickelt, welche die Kontrolle des Werkstücks schon während des Bauprozesses ermöglicht. Für eine optimale Auslegung der Messtechnik wird ein Vorgehen zur Genauigkeitsanalyse am Beispiel eines selektiven Lasersinterprozesses durchgeführt. Darüber hinaus werden die auftretenden systematischen Abweichungen untersucht.   Generative manufacturing processes allow an economical production of small batch sizes. In order to ensure this advantage by good quality, a measurement system is in development which is able to monitor the workpiece during the manufacturing process. For an optimal design of the measurement system, an approach is presented for the evaluation of the accuracy on the example of a selective laser sintering process, followed by an analysis of the detected systematical deviations.

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