Effects of Attack Angle and Relative Thickness of Novel Wing-Shaped Turbulators on Turbulent Hydrothermal Performance in a Two-Pass Square Channel

2020 ◽  
Author(s):  
Tong-Miin Liou ◽  
Chieh-Chu Chen ◽  
Chun-Sheng Wang
Keyword(s):  
Nusselt Number ◽  
Fused Deposition Modeling ◽  
Transverse Velocity ◽  
Attack Angle ◽  
Ir Camera ◽  
Pressure Drops ◽  
Square Channel ◽  
Fused Deposition ◽  
Flow Parameters ◽  
Number Ratio

Abstract This work aims to combine the effects of the near wall and core flow disturbance by proposing novel wing-shaped tabulators. The new tabulators are fabricated with the fused deposition modeling (3D printing) technology. To explore their effects on detailed flow fields, local temperature distributions, and pressure drops in a two-pass square channel, Particle Image Velocimetry (PIV), Infrared Thermography (IR camera), and pressure transducer measurements are performed. The tabulator pitch, clearance, and truncation gap ratio based on the channel hydraulic diameter of 45.5 mm are respectively fixed at 0.7, 0.25 and 0.06. Varied parameters include tabulator attack angle (α = 10°, 15°, 20°, and 30°), maximum thickness to chord line ratio (t/C = 0.08, 0.13, 0.16, 0.20, and 0.23), and bulk Reynolds number (Re = 5,000–20,000). From the experimental results and flow parameters analyzed, the dimensionless spanwise-averaged mean transverse velocity and cross-sectionally averaged vorticity magnitude are identified to be the most relevant ones to spanwise-averaged local Nusselt number ratio in the first and second pass. Among all examined cases and previous data with Fanning friction factor ratio (f¯/fo) less than 50, the case with α = 20° and t/C = 0.20 attains the highest thermal performance factor and overall Nusselt number ratio (Nu¯/Nuo) up to 1.68 and 5.36, respectively. Furthermore, empirical correlations of Nu¯/Nuo and f¯/fo versus α, t/C, and Re are proposed.

Effects of Attack Angle and Relative Thickness of Novel Wing-Shaped Turbulators on Turbulent Hydrothermal Performance in a Two-Pass Square Channel

2021 ◽  
pp. 1-7
Author(s):  
Tong-Miin Liou ◽  
Chieh Chu Chen ◽  
Chun-Sheng Wang
Keyword(s):  
Nusselt Number ◽  
Fused Deposition Modeling ◽  
Transverse Velocity ◽  
Attack Angle ◽  
Ir Camera ◽  
Pressure Drops ◽  
Square Channel ◽  
Fused Deposition ◽  
Flow Parameters ◽  
Number Ratio

Abstract This work aims to combine the effects of the near wall and core flow disturbance by proposing novel wing-shaped turbulators. The new turbulators are fabricated with the fused deposition modeling (3D printing) technology. To explore their effects on detailed flow fields, local temperature distributions, and pressure drops in a two-pass square channel, Particle Image Velocimetry (PIV), Infrared Thermography (IR camera), and pressure transducer measurements are performed. The turbulator pitch, clearance, and truncation gap ratio based on the channel hydraulic diameter of 45.5 mm are respectively fixed at 0.7, 0.25 and 0.06. Varied parameters include turbulator attack angle (α = 10°, 15°, 20°, and 30°), maximum thickness to chord line ratio (t/C = 0.08, 0.13, 0.16, 0.20, and 0.23), and bulk Reynolds number (Re = 5,000-20,000). From the experimental results and flow parameters analyzed, the dimensionless spanwise-averaged mean transverse velocity and cross-sectionally averaged vorticity magnitude are identified to be the most relevant ones to spanwise-averaged local Nusselt number ratio in the first and second pass. Among all examined cases and previous data with Fanning friction factor ratio (f¯/fo) less than 50, the case with α = 20° and t/C = 0.20 attains the highest thermal performance factor and overall Nusselt number ratio (Nu¯/Nuo) up to 1.68 and 5.36, respectively. Furthermore, empirical correlations of Nu¯/Nuo and f¯/fo versus α, t/C, and Re are proposed.

scholarly journals DEVELOPMENT OF AN EXPERIMENTAL AXIAL STAND COMPRESSORS USING ADDITIVE TECHNOLOGIES

2021 ◽  
pp. 33-42
Author(s):  
Vladislav Savchenko ◽  
◽  
Vitalii Blinov ◽  
Sergei Shamanin ◽  
◽  
...  
Keyword(s):  
Fused Deposition Modeling ◽  
General Scheme ◽  
Three Dimensional ◽  
Axial Compressor ◽  
Calculated Data ◽  
Educational Process ◽  
Calculation Methods ◽  
Two Stage ◽  
Fused Deposition ◽  
Flow Parameters

In practice, the creation of compressor units is impossible without a large amount of experimental work. A lot of money is being invested in solving this problem, and many people participate in testing. Almost all calculation methods that are used in design are experimental and theoretical. In this regard, the modernization of calculation methods is inextricably linked with the development of experimental research, improvement of means and methods of measurements. In this paper, the created miniature experimental stand of a two-stage axial compressor is described, the general scheme of the stand is shown, the systems are described in detail. Several experiments were carried out at different speeds of rotation with different loads, the results were analyzed. Methods for obtaining characteristics of axial compressors using a software package for numerical three-dimensional thermodynamics modeling are presented. The described compressor unit has a set of sensors for collecting flow parameters in different planes. The signals from the sensors are processed by an eight-bit microcontroller. The stand is made of plastic using fused deposition modeling (FDM) on a 3D printer. Preliminary calculations of the strength of the rotor structure elements were carried out, the materials recommended for the manufacture of the installation were determined. The stand is proposed to be used for the design and optimization of two-stage compressor, as well as in the educational process. Also, in this article describes a constructed numerical model for studying the flow parameters of a compressor, presents the results of comparing some experimental and calculated data, constructs a flow characteristic, estimates the measurement uncertainty, and formulates several recommendations.

Biodegradable 3D Printed Polymer Microneedles for Transdermal Drug Delivery

2018 ◽  
Author(s):  
Michael A. Luzuriaga ◽  
Danielle R. Berry ◽  
John C. Reagan ◽  
Ronald A. Smaldone ◽  
Jeremiah J. Gassensmith
Keyword(s):  
Drug Delivery ◽  
3D Printing ◽  
Transdermal Drug Delivery ◽  
Fused Deposition Modeling ◽  
Fused Deposition ◽  
Modeling Software ◽  
Deposition Modeling ◽  
3D Printed ◽  
Microfabrication Technique ◽  
Mechanical Strengths

Biodegradable polymer microneedle (MN) arrays are an emerging class of transdermal drug delivery devices that promise a painless and sanitary alternative to syringes; however, prototyping bespoke needle architectures is expensive and requires production of new master templates. Here, we present a new microfabrication technique for MNs using fused deposition modeling (FDM) 3D printing using polylactic acid, an FDA approved, renewable, biodegradable, thermoplastic material. We show how this natural degradability can be exploited to overcome a key challenge of FDM 3D printing, in particular the low resolution of these printers. We improved the feature size of the printed parts significantly by developing a post fabrication chemical etching protocol, which allowed us to access tip sizes as small as 1 μm. With 3D modeling software, various MN shapes were designed and printed rapidly with custom needle density, length, and shape. Scanning electron microscopy confirmed that our method resulted in needle tip sizes in the range of 1 – 55 µm, which could successfully penetrate and break off into porcine skin. We have also shown that these MNs have comparable mechanical strengths to currently fabricated MNs and we further demonstrated how the swellability of PLA can be exploited to load small molecule drugs and how its degradability in skin can release those small molecules over time.

Thermal characterization of ABS-Graphene blended three dimensional printed functional prototypes for electro chemical energy storage

2018 ◽  
Vol 1 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Kamaljit Singh Boparai ◽  
Rupinder Singh
Keyword(s):  
Energy Storage ◽  
Structural Changes ◽  
Fused Deposition Modeling ◽  
Morphological Changes ◽  
Three Dimensional ◽  
Thermal Characterization ◽  
Chemical Energy ◽  
Flow Index ◽  
Fused Deposition

This study highlights the thermal characterization of ABS-Graphene blended three dimensional (3D) printed functional prototypes by fused deposition modeling (FDM) process. These functional prototypes have some applications as electro-chemical energy storage devices (EESD). Initially, the suitability of ABS-Graphene composite material for FDM applications has been examined by melt flow index (MFI) test. After establishing MFI, the feedstock filament for FDM has been prepared by an extrusion process. The fabricated filament has been used for printing 3D functional prototypes for printing of in-house EESD. The differential scanning calorimeter (DSC) analysis was conducted to understand the effect on glass transition temperature with the inclusion of Graphene (Gr) particles. It has been observed that the reinforced Gr particles act as a thermal reservoir (sink) and enhances its thermal/electrical conductivity. Also, FT-IR spectra realized the structural changes with the inclusion of Gr in ABS matrix. The results are supported by scanning electron microscopy (SEM) based micrographs for understanding the morphological changes.

An Update on the Use of Alginate in Additive Biofabrication Techniques

2019 ◽  
Vol 25 (11) ◽  
pp. 1249-1264 ◽  
Author(s):  
Amoljit Singh Gill ◽  
Parneet Kaur Deol ◽  
Indu Pal Kaur
Keyword(s):  
Fused Deposition Modeling ◽  
Low Cost ◽  
Selective Laser Sintering ◽  
Layer By Layer ◽  
Three Dimension ◽  
Anionic Polymer ◽  
Fused Deposition ◽  
The Status ◽  
Deposition Modeling ◽  
Extrusion Printing

Background: Solid free forming (SFF) technique also called additive manufacturing process is immensely popular for biofabrication owing to its high accuracy, precision and reproducibility. Method: SFF techniques like stereolithography, selective laser sintering, fused deposition modeling, extrusion printing, and inkjet printing create three dimension (3D) structures by layer by layer processing of the material. To achieve desirable results, selection of the appropriate technique is an important aspect and it is based on the nature of biomaterial or bioink to be processed. Result & Conclusion: Alginate is a commonly employed bioink in biofabrication process, attributable to its nontoxic, biodegradable and biocompatible nature; low cost; and tendency to form hydrogel under mild conditions. Furthermore, control on its rheological properties like viscosity and shear thinning, makes this natural anionic polymer an appropriate candidate for many of the SFF techniques. It is endeavoured in the present review to highlight the status of alginate as bioink in various SFF techniques.

Extrusion-Based 3D Printing for Pharmaceuticals: Contemporary Research and Applications

2019 ◽  
Vol 24 (42) ◽  
pp. 4991-5008 ◽  
Author(s):  
Mohammed S. Algahtani ◽  
Abdul Aleem Mohammed ◽  
Javed Ahmad
Keyword(s):  
Cosmetic Surgery ◽  
Fused Deposition Modeling ◽  
Personalised Medicine ◽  
Organ Transplant ◽  
Three Dimensional ◽  
Dosage Forms ◽  
Release Profile ◽  
Small Scale ◽  
Drug Release Profile ◽  
Fused Deposition

Three-dimensional printing (3DP) has a significant impact on organ transplant, cosmetic surgery, surgical planning, prosthetics and other medical fields. Recently, 3 DP attracted the attention as a promising method for the production of small-scale drug production. The knowledge expansion about the population differences in metabolism and genetics grows the need for personalised medicine substantially. In personalised medicine, the patient receives a tailored dose and the release profile is based on his pharmacokinetics data. 3 DP is expected to be one of the leading solutions for the personalisation of the drug dispensing. This technology can fabricate a drug-device with complicated geometries and fillings to obtain the needed drug release profile. The extrusionbased 3 DP is the most explored method for investigating the feasibility of the technology to produce a novel dosage form with properties that are difficult to achieve using the conventional industrial methods. Extrusionbased 3 DP is divided into two techniques, the semi-solid extrusion (SSE) and the fused deposition modeling (FDM). This review aims to explain the extrusion principles behind the two techniques and discuss their capabilities to fabricate novel dosage forms. The advantages and limitations observed through the application of SSE and FDM for fabrication of drug dosage forms were discussed in this review. Further exploration and development are required to implement this technology in the healthcare frontline for more effective and personalised treatment.

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