CHARACTERIZATION OF SPLASH-PLATE ATOMIZERS USING NUMERICAL SIMULATIONS

2007 ◽  
Vol 17 (4) ◽  
pp. 347-380 ◽  
Author(s):  
Mohammad P. Fard ◽  
Denise Levesque ◽  
Stuart Morrison ◽  
Nasser Ashgriz ◽  
J. Mostaghimi
Keyword(s):  
Numerical Simulations

scholarly journals A Moving 3D Laser Scanner for Automated Underbridge Inspection

2017 ◽  
Author(s):  
Marco Tarabini ◽  
Hermes Giberti ◽  
Silvio Giancola ◽  
Matteo Sgrenzaroli ◽  
Remo Sala ◽  
...  
Keyword(s):  
Measurement Uncertainty ◽  
Numerical Simulations ◽  
Relative Motion ◽  
Reference System ◽  
Complete System ◽  
Laser Scanner ◽  
Bridge Model ◽  
Fixed Reference ◽  
Scanning Head

Recent researches proved that the underbridge geometry can be reconstructed by mounting a 3D laser scanner on a motorized cart travelling on a walkway located under the bridge. The walkway is moved by a truck and the accuracy of the bridge model depends on the accuracy of the trajectory of the scanning head with respect to a fixed reference system. In this paper, we describe the metrological characterization of a method that uses non-contact systems to identify the relative motion of the cart with respect to the walkway; the orientation of the walkway with respect to the bridge is determined using inclinometers and optical rails, while the position of the truck with respect to the bridge is measured using a conventional odometer.  The measurement uncertainty of the proposed system was initially evaluated by numerical simulations and successively verified by experiments in laboratory conditions. The complete system has then been tested in operative conditions; the validity of the proposed approach has been demonstrated by comparing the geometry of buildings reconstructed with the proposed system with the geometry obtained with a static scan. Results evidenced that the errors are approximately 6 mm.

Experimental Characterization of a T-Shaped Programmable Multistable Mechanism

2018 ◽  
Vol 140 (9) ◽  
Author(s):  
Mohamed Zanaty ◽  
Simon Henein
Keyword(s):  
Numerical Simulations ◽  
Reaction Force ◽  
Experimental Measurements ◽  
Experimental Characterization ◽  
Stable States ◽  
Stability Behavior ◽  
The Stability ◽  
Force Characteristics ◽  
Good Agreement

Programmable multistable mechanisms (PMM) exhibit a modifiable stability behavior in which the number of stable states, stiffness, and reaction force characteristics are controlled via their programming inputs. In this paper, we present experimental characterization for the concept of stability programing introduced in our previous work (Zanaty et al., 2018, “Programmable Multistable Mechanisms: Synthesis and Modeling,” ASME J. Mech. Des., 140(4), p. 042301.) A prototype of the T-combined axially loaded double parallelogram mechanisms (DPM) with rectangular hinges is manufactured using electrodischarge machining (EDM). An analytical model based on Euler–Bernoulli equations of the T-mechanism is derived from which the stability behavior is extracted. Numerical simulations and experimental measurements are conducted on programming the mechanism as monostable, bistable, tristable, and quadrastable, and show good agreement with our analytical derivations within 10%.

Numerical Simulation of Offshore Pipeline Installation by Lateral Deflection Procedure

2007 ◽  
Author(s):  
Danilo Machado Lawinscky da Silva ◽  
Rodrigo Almeida Bahiense ◽  
Breno Pinheriro Jacob ◽  
Fernando Gomes da Silva Torres ◽  
Antonio Roberto Medeiros ◽  
...  
Keyword(s):  
Numerical Simulation ◽  
Numerical Simulations ◽  
Computational Tool ◽  
Lateral Deflection ◽  
Correct Definition ◽  
Offshore Pipeline ◽  
Definition Of

Conventional offshore pipeline installation operations in Brazil have been performed in an S-Lay procedure employing the BGL-1 barge, owned by Petrobras. However, this procedure has some limits, and may not be feasible in some particular scenarios. Therefore, the objective of this work is to present the numerical simulation of an alternative pipeline installation procedure. This procedure basically consists of performing the pipeline assembly on shore, and deflecting it to the sea using a tug boat. The numerical simulations employ the SITUA-Prosim computational tool, which is able to incorporate the correct definition of the seabed and shore from bathymetric curves. An actual pipeline installation by this lateral deflection procedure is analyzed and discussed. The characterization of the procedure passes through the determination of the better velocity and direction of the tug boat in order to minimize the efforts on the pipeline (especially due to the curvatures).

Thermodynamic Characterization of Supersonic Expansions Using Shadowgraphy and Numerical Simulations

2013 ◽  
Author(s):  
Juan M. Lorenzi ◽  
Carlos A. Rinaldi ◽  
Cynthia Toro Salazar ◽  
Mayo Villagran Muñiz ◽  
Salvador C. Ortiz
Keyword(s):  
Numerical Simulations ◽  
Thermodynamic Characterization ◽  
Supersonic Expansions

Simulation, Fabrication and Characterization of 4500V 4H-SiC JBS Diode

2014 ◽  
Vol 778-780 ◽  
pp. 800-803 ◽  
Author(s):  
Run Hua Huang ◽  
Gang Chen ◽  
Song Bai ◽  
Rui Li ◽  
Yun Li ◽  
...  
Keyword(s):  
Numerical Simulations ◽  
Breakdown Voltage ◽  
Epitaxial Layer ◽  
Doping Level ◽  
Electrical Characteristics ◽  
Edge Termination ◽  
Fabrication And Characterization ◽  
Drift Layer

4H-SiC JBS diode with breakdown voltage higher than 4.5 kV, has been successfully fabricated on 4H-SiC wafers with epitaxial layer. In this paper we report the design, the fabrication, and the electrical characteristics of 4H-SiC JBS diode. Numerical simulations have been performed to select the doping level and thickness of the drift layer and the effectiveness of the edge termination technique. The epilayer properties of the N-type are 55 μm with a doping of 9×1014cm−3. The diodes were fabricated with a floating guard rings edge termination. The on-state voltage was 4V at JF=80 A/cm2

scholarly journals A family of phase masks for broadband coronagraphy example of the wrapped vortex phase mask theory and laboratory demonstration

2020 ◽  
Vol 635 ◽  
pp. A11
Author(s):  
R. Galicher ◽  
E. Huby ◽  
P. Baudoz ◽  
O. Dupuis
Keyword(s):  
Numerical Simulations ◽  
New Technology ◽  
Phase Mask ◽  
High Attenuation ◽  
Star Image ◽  
Vortex Phase ◽  
New Type ◽  
Previous Solution ◽  
Spectral Ranges

Context. Future instruments need efficient coronagraphs over large spectral ranges to enable broadband imaging or spectral characterization of exoplanets that are 108 times fainter than their star. Several solutions have been proposed. Pupil apodizers can attenuate the star intensity by a factor of 1010 but they only transmit a few percent of the light of the planet. Cascades of phase and/or amplitude masks can both attenuate the starlight and transmit most of the planet light, but the number of optics that require alignment makes this solution impractical for an instrument. Finally, vector phase masks can be used to detect faint sources close to bright stars but they require the use of high-quality circular polarizers and, as in the previous solution, this leads to a complex instrument with numerous optics that require alignment and stabilization. Aims. We propose simple coronagraphs that only need one scalar phase mask and one binary Lyot stop providing high transmission for the planet light (> 50%) and high attenuation of the starlight over a large spectral bandpass (∼30%) and a 360° field-of-view. Methods. From mathematical considerations, we find a family of 2D phase masks optimized for an unobscured pupil. One mask is an azimuthal wrapped vortex phase ramp. We probe its coronagraphic performance using numerical simulations and laboratory tests. Results. From numerical simulations, we predict the wrapped vortex can attenuate the peak of the star image by a factor of 104 over a 29% bandpass and 105 over a 18% bandpass with transmission of more than 50% of the planet flux at ∼4λ/D. We confirm these predictions in the laboratory in visible light between 550 and 870 nm. We also obtain laboratory dark hole images in which exoplanets with fluxes that are 3 × 10−8 times the host star flux could be detected at 3σ. Conclusions. Taking advantage of a new technology for etching continuous 2D functions, a new type of mask can be easily manufactured opening up new possibilities for broadband coronagraphy.

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