scholarly journals Modeling of microwave applicators with an excitation through the wave guide using TLM method

2005 ◽  
Vol 2 (2) ◽  
pp. 137-146
Author(s):  
Tijana Randjelovic ◽  
Jugoslav Jokovic ◽  
Bratislav Milovanovic
Keyword(s):  
Experimental Results ◽  
Wave Guide ◽  
Analytical Results ◽  
Resonant Modes ◽  
Impulse Excitation ◽  
Wave Guides ◽  
Tlm Method ◽  
Microwave Applicator ◽  
Good Agreement ◽  
Microwave Applicators

In this paper, a real microwave applicator with a wave guide used to launch the energy from the source into the cavity is analyzed using 3D TLM method. In order to investigate the influence of the positions and number of feed wave guides to the number of the resonant modes inside the cavity, obtained results are compared with analytical results and results obtained by using TLM software with an impulse excitation as well. TLM method is applied to the both empty and loaded rectangular metallic cavity, and a very good agreement between simulated and experimental results is achieved.

A Field Method of Determining Gas Turbine Meter Performance

1970 ◽  
Vol 92 (4) ◽  
pp. 724-731 ◽  
Author(s):  
W. F. Z. Lee ◽  
H. J. Evans
Keyword(s):  
Gas Turbine ◽  
Field Method ◽  
Experimental Results ◽  
Inexpensive Method ◽  
Analytical Results ◽  
The Relationship ◽  
Good Agreement

The need for a simple and inexpensive method for field checking gas turbine meters exists. One such method called the “spin test” is described in this paper. The relationship between the change of “rotor coast time” of the spin test and the change of meter accuracy due to change of mechanical friction is formulated. Experimental results on two different 6-in. gas turbine meters are presented and show good agreement with analytical results.

On the Stabilizing Methods of Externally Pressurized Thrust Gas Bearings

1967 ◽  
Vol 89 (3) ◽  
pp. 283-289 ◽  
Author(s):  
Haruo Mori ◽  
Atsunobu Mori
Keyword(s):  
Experimental Results ◽  
Fluid Restriction ◽  
Theoretical Base ◽  
Gas Bearings ◽  
Analytical Results ◽  
Supply Line ◽  
Gas Supply ◽  
Good Agreement

Two kinds of stabilizing methods for externally pressurized thrust gas bearings are presented and analyzed. Both stabilizers of them are composed of fluid restriction and capacitance. The first type of stabilizer, which has been investigated by Loch, has a pair of restriction and capacitance attached additionally to the bearing recess, and the second type has the pair inserted into the gas-supply line to the bearing recess. Since the theoretical base of Loch’s analysis had questionable points, the analysis by the authors is started from a new and different standpoint and applied to the second type as well as to the first type. Experimental results show good agreement with the analytical results and the design of the stabilizers has been established.

scholarly journals Experimental Research on Static Stiffness of the Planetary Roller Screw Mechanism

2020 ◽  
Vol 306 ◽  
pp. 02002
Author(s):  
Ma Shangjun ◽  
Wu Guanyu ◽  
Zhang Jianxin ◽  
Liu Geng
Keyword(s):  
Elastic Deformation ◽  
Experimental Results ◽  
Static Stiffness ◽  
Machining Error ◽  
Analytical Results ◽  
Roller Screw ◽  
Screw Mechanism ◽  
Stiffness Characteristics ◽  
Assembly Error ◽  
Good Agreement

This paper investigates the static stiffness characteristics of the planetary roller screw mechanism (PRSM). Firstly, an analytical model of elastic deformation in the PRSM considering contact deformation, combined deformation of screw shaft and thread deformations is established. Then, an accuracy coefficient is introduced to take into account the effect of machining error and assembly error on elastic deformation. Secondly, the stiffness tests of the PRSM are performed under different loads and nut positions. Lastly, the correctness of the analytical results is verified via the comparison with experimental results. The results show that the analytical results are in good agreement with the experimental results, and the stiffness variations under different loads and nut positions are obtained.

Inducing Frictional Force to Enhance the Transient Response in Beams

2019 ◽  
Vol 22 (2) ◽  
pp. 88-93
Author(s):  
Hamed Khanger Mina ◽  
Waleed K. Al-Ashtrai
Keyword(s):  
Numerical Analysis ◽  
Transient Response ◽  
Frictional Force ◽  
Damping Ratio ◽  
Experimental Results ◽  
Damping Capacity ◽  
Tightening Force ◽  
Contact Areas ◽  
Good Agreement ◽  
Ansys Workbench

This paper studies the effect of contact areas on the transient response of mechanical structures. Precisely, it investigates replacing the ordinary beam of a structure by two beams of half the thickness, which are joined by bolts. The response of these beams is controlled by adjusting the tightening of the connecting bolts and hence changing the magnitude of the induced frictional force between the two beams which affect the beams damping capacity. A cantilever of two beams joined together by bolts has been investigated numerically and experimentally. The numerical analysis was performed using ANSYS-Workbench version 17.2. A good agreement between the numerical and experimental results has been obtained. In general, results showed that the two beams vibrate independently when the bolts were loosed and the structure stiffness is about 20 N/m and the damping ratio is about 0.008. With increasing the bolts tightening, the stiffness and the damping ratio of the structure were also increased till they reach their maximum values when the tightening force equals to 8330 N, where the structure now has stiffness equals to 88 N/m and the damping ratio is about 0.062. Beyond this force value, increasing the bolts tightening has no effect on stiffness of the structure while the damping ratio is decreased until it returned to 0.008 when the bolts tightening becomes immense and the beams behave as one beam of double thickness.

PHOTOINDUCED NONLINEAR OCTUPOLAR POLARIZATION: TRANSIENT AND PERMANENT REGIMES

1996 ◽  
Vol 05 (04) ◽  
pp. 653-670 ◽  
Author(s):  
CÉLINE FIORINI ◽  
JEAN-MICHEL NUNZI ◽  
FABRICE CHARRA ◽  
IFOR D.W. SAMUEL ◽  
JOSEPH ZYSS
Keyword(s):  
Theoretical Analysis ◽  
Second Harmonic ◽  
Experimental Results ◽  
Polar Field ◽  
Rotational Spectrum ◽  
Dual Frequency ◽  
One Dimensional ◽  
Ethyl Violet ◽  
Disperse Red 1 ◽  
Good Agreement

An original poling method using purely optical means and based on a dual-frequency interference process is presented. We show that the coherent superposition of two beams at fundamental and second-harmonic frequencies results in a polar field with an irreducible rotational spectrum containing both a vector and an octupolar component. This enables the method to be applied even to molecules without a permanent dipole such as octupolar molecules. After a theoretical analysis of the process, we describe different experiments aiming at light-induced noncentrosymmetry performed respectively on one-dimensional Disperse Red 1 and octupolar Ethyl Violet molecules. Macroscopic octupolar patterning of the induced order is demonstrated in both transient and permanent regimes. Experimental results show good agreement with theory.

scholarly journals Comparison of Experimental and Numerical Transient Drop Deformation during Transition through Orifices in High-Pressure Homogenizers

2021 ◽  
Vol 5 (3) ◽  
pp. 32
Author(s):  
Benedikt Mutsch ◽  
Peter Walzel ◽  
Christian J. Kähler
Keyword(s):  
High Pressure ◽  
Visual Analysis ◽  
Imaging Technique ◽  
Extensional Flow ◽  
Droplet Breakup ◽  
Experimental Results ◽  
Drop Deformation ◽  
Droplet Deformation ◽  
Shadow Imaging ◽  
Good Agreement

The droplet deformation in dispersing units of high-pressure homogenizers (HPH) is examined experimentally and numerically. Due to the small size of common homogenizer nozzles, the visual analysis of the transient droplet generation is usually not possible. Therefore, a scaled setup was used. The droplet deformation was determined quantitatively by using a shadow imaging technique. It is shown that the influence of transient stresses on the droplets caused by laminar extensional flow upstream the orifice is highly relevant for the droplet breakup behind the nozzle. Classical approaches based on an equilibrium assumption on the other side are not adequate to explain the observed droplet distributions. Based on the experimental results, a relationship from the literature with numerical simulations adopting different models are used to determine the transient droplet deformation during transition through orifices. It is shown that numerical and experimental results are in fairly good agreement at limited settings. It can be concluded that a scaled apparatus is well suited to estimate the transient droplet formation up to the outlet of the orifice.

Simulation of Sphere’s Motion Induced by Shock Waves

2012 ◽  
Vol 134 (10) ◽  
Author(s):  
Dan Igra ◽  
Ozer Igra ◽  
Lazhar Houas ◽  
Georges Jourdan
Keyword(s):  
Shock Waves ◽  
Drag Coefficient ◽  
Drag Force ◽  
Stationary Flow ◽  
Experimental Results ◽  
Experimental Findings ◽  
Sphere Drag ◽  
Simulation Scheme ◽  
Good Agreement

Simulations of experimental results appearing in Jourdan et al. (2007, “Drag Coefficient of a Sphere in a Non-Stationary Flow: New Results,”Proc. R. Soc. London, Ser. A, 463, pp. 3323–3345) regarding acceleration of a sphere by the postshock flow were conducted in order to find the contribution of the various parameters affecting the sphere drag force. Based on the good agreement found between present simulations and experimental findings, it is concluded that the proposed simulation scheme could safely be used for evaluating the sphere’s motion in the postshock flow.

Viscoelastic Deformation of PC/ABS Alloy

2007 ◽  
Vol 353-358 ◽  
pp. 1229-1232
Author(s):  
Z.N. Yin ◽  
L.F. Fan ◽  
Tie Jun Wang
Keyword(s):  
Dynamic Mechanical Analysis ◽  
Relaxation Modulus ◽  
Mechanical Analysis ◽  
Experimental Results ◽  
Viscoelastic Deformation ◽  
Dynamic Mechanical ◽  
Storage And Loss Moduli ◽  
Static Relaxation ◽  
Comparison Of The Results ◽  
Good Agreement

Dynamic Mechanical Analysis (DMA) and static relaxation tests are carried out to study the viscoelastic deformation of PC/ABS alloy with blending ratio of PC to ABS being 50/50. A modified approach is developed to calculate the relaxation modulus of PC/ABS alloy from the DMA experimental results of storage and loss moduli. Comparison of the results obtained from DMA and static relaxation tests is presented and good agreement is found.

Influence of the Morphology on the Optical Properties of Nanocermet Films: A Renormalization Approach

1990 ◽  
Vol 195 ◽  
Author(s):  
S. Berthier ◽  
K. Driss-Khodja
Keyword(s):  
Optical Properties ◽  
Critical Exponents ◽  
Inhomogeneous Media ◽  
Experimental Results ◽  
Percolation Transition ◽  
Position Space ◽  
Renormalization Approach ◽  
2D And 3D ◽  
Good Agreement ◽  
Effective Medium Models

ABSTRACTIn order to take into account the actual morphology of the inhomogeneous media, we have developed, effective medium models based on a 2D and 3D position space renormalization /1,2/. These models predict the dipolar resonance and the percolation transition with critical exponents in good agreement with theoretical values and fairly reproduce most of the experimental results, whatever the concentration is. Further more, this allows a valuable comparison of the predictions of our models when applied on different lattices like real digitized TEM of cermet films or randomly occupied lattices.

EQUATION OF STATE FOR HOT GLUON PLASMA WITH EFFECTIVE TWO LOOPS

2001 ◽  
Vol 16 (27) ◽  
pp. 1751-1759 ◽  
Author(s):  
XIN WANG ◽  
JIARONG LI ◽  
JUEPING LIU
Keyword(s):  
Equation Of State ◽  
Gluon Plasma ◽  
Physical Parameters ◽  
Finite Width ◽  
Debye Screening ◽  
Debye Mass ◽  
Analytical Results ◽  
Good Agreement ◽  
Hard Thermal Loops

We present analytical results for the equation of state for hot gluon plasma obtained with an effective perturbation based on hard thermal loops resummation theory. The effective two-loop results depend on Debye screening and finite width of gluons as physical parameters. Considering next-to-leading Debye mass and finite width effects, we find the equation of state to be in good agreement with recent lattice results for T≳2T c .

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