scholarly journals Road-to-Vehicle Communications With Time-Dependent Anonymity: A Lightweight Construction and Its Experimental Results

2018 ◽  
Vol 67 (2) ◽  
pp. 1582-1597 ◽  
Author(s):  
Keita Emura ◽  
Takuya Hayashi
Author(s):  
E. de Langre ◽  
J. L. Riverin ◽  
M. J. Pettigrew

The time dependent forces resulting from a two-phase air-water mixture flowing in an elbow and a tee are measured. Their magnitudes as well as their spectral contents are analyzed. Comparison is made with previous experimental results on similar systems. For practical applications a dimensionless form is proposed to relate the characteristics of these forces to the parameters defining the flow and the geometry of the piping.


Author(s):  
M. Caplan ◽  
W.A. Bongers ◽  
M. Valentini ◽  
W.H. Urbanus ◽  
A.G.A. Verhoeven ◽  
...  

2005 ◽  
Vol 128 (2) ◽  
pp. 359-369 ◽  
Author(s):  
Rafael Ballesteros-Tajadura ◽  
Sandra Velarde-Suárez ◽  
Juan Pablo Hurtado-Cruz ◽  
Carlos Santolaria-Morros

In this work, a numerical model has been applied in order to obtain the wall pressure fluctuations at the volute of an industrial centrifugal fan. The numerical results have been compared to experimental results obtained in the same machine. A three-dimensional numerical simulation of the complete unsteady flow on the whole impeller-volute configuration has been carried out using the computational fluid dynamics code FLUENT®. This code has been employed to calculate the time-dependent pressure both in the impeller and in the volute. In this way, the pressure fluctuations in some locations over the volute wall have been obtained. The power spectra of these fluctuations have been obtained, showing an important peak at the blade passing frequency. The amplitude of this peak presents the highest values near the volute tongue, but the spatial pattern over the volute extension is different depending on the operating conditions. A good agreement has been found between the numerical and the experimental results.


2003 ◽  
Vol 18 (30) ◽  
pp. 2083-2098
Author(s):  
Gabriella Sciolla

Recent measurements of time-dependent CP-asymmetries at the B-factories have led to substantial progress in our understanding of CP-violation. In this paper, we review some of these experimental results and discuss their implications in the Standard Model and their sensitivity to New Physics.


2008 ◽  
Author(s):  
D. E. Greenfield ◽  
M. A. Monastyrskiy ◽  
V. I. Lozovoi ◽  
M. Ya. Schelev ◽  
Yu. N. Serdyuchenko

Author(s):  
Sohila A. El-Khouly ◽  
Amr H. Zaher ◽  
Ehab F. Sadek ◽  
Khalid M. Hilal

Lightweight Concrete with polystyrene foam particles (LWC) was obtained through the use of polystyrene foam as a partial aggregate’s replacement to reduce the concrete dry unit weight from 23 KN/m3 to 18.50 KN/m3. This research presents an experimental and theoretical investigation in the long-term behavior of LWC in compression and flexure. Two experimental programs were conducted; namely, creep and shrinkage of LWC under compressive loading test, and the time-dependent flexural behavior of reinforced LWC beams. The main variable in the first experimental program was the percentage of sustained load, while the main variables in the second experimental program were the percentage of sustained load and the percentage of compression reinforcement. Experimental results showed that LWC exhibits a significantly higher time-dependent strain (shrinkage plus creep) than normal weight concrete (NWC) under sustained compressive load and at the same compressive strength, with an increasing percentage about 9%. The creep strains of LWC seemed to be proportional to the stress to strength ratio. The timedependent deflections of the LWC beams were higher than those of NWC beams with increasing percentage about 25%. Addition of compression steel reinforcement (As`) to LWC beams reduced time-dependent deflections. Sustained load level and LWC time-dependent deflection were directly proportional. Finally, models and equations proposed by different codes were used to evaluate the obtained experimental results. From the theoretical study, it was found that Bazant-Baweja B3 Model gave superior shrinkage strains prediction for LWC. The ACI 209R-92 presented preferable predictions of creep strain and time-dependent deflection of LWC.


Author(s):  
F.-K. Benra ◽  
H. J. Dohmen ◽  
M. Sommer

The composition of sewage water with partially large portions of fibers and solids requires a special pump design, in order to avoid operational disturbances by clogging. In most applications for sewage water transport, single-stage pumps with single-blade impellers are used. With this special impeller geometry largest flow channels can be realized. So fibers and solids up to an appropriate size can be transported by the pump. This minimum impeller blade number however brings disadvantages for pump operation. The development of a pressure and a suction surface of the blade gives an asymmetric pressure distribution at the perimeter of the rotor outlet and a periodically unsteady flow field arises. In a numerical approach the time accurate flow in a single-blade centrifugal pump has been calculated by solving the 3-dimensional time dependent Reynolds averaged Navier-Stokes equations (URANS) in a wide range of pump operation. The investigation of the flow included all details between suction flange and pressure flange of the pump. The numerical results show a strong dependence from impeller position for all flow parameters. For the investigated operating points strong vortices have been obtained at particular impeller positions. Experimental results have been used to verify the numerical results of time dependent flow in the single-blade pump. The computed flow field has been compared to results which were obtained from optical measurements of flow velocities by Particle Image Velocimetry at different impeller positions. A very good qualitative agreement between measurements and calculations has been obtained for all investigated operating points.


1971 ◽  
Vol 93 (3) ◽  
pp. 875-882 ◽  
Author(s):  
M. R. Snoey ◽  
M. G. Katona

This study was initiated to: (1) perform an analytical structural analysis on an acrylic pressure hull, (2) compare the analytical results with all available experimental results, and (3) present an operating-depth curve. The design analyzed was a pressure hull incorporating twelve spherical pentagons of acrylic plastic bonded together to form a sphere with an outside diameter of 66 in. and a wall thickness of 2.5 in. Conical steel penetrations were located at the two poles. The experimental results were obtained from strain-gage data from two independent pressure tests to 500 psi on two acrylic hulls of the same design. The analysis on the structure was performed with a finite-element computer code with particular emphasis on the acrylic-steel boundary. The boundary conditions at the acrylic-steel interface were two extreme cases: perfectly fixed and perfectly free. A time-dependent yield-failure criterion for acrylic plastic was combined with the structural analysis to provide an operating-depth curve as a function of both time and temperature. Comparison of analytical and experimental results indicated excellent agreement. At a temperature of 70 deg F and a maximum of 50 hr load duration, the acrylic hull can operate to 1000 ft with a safety factor of 1.5 based on yield and a safety factor of 2.6 based on collapse.


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