A New Model for Interpreting Experimental Data from a Circular Waveguide Cavity

Author(s):  
William A. Huting
2008 ◽  
Vol 74 (3) ◽  
pp. 391-429 ◽  
Author(s):  
G. HERDRICH ◽  
D. PETKOW

AbstractThe development of the inductively driven plasma wind tunnel PWK3, which enables the electrodeless generation of high-enthalpy plasmas for the development of heat shield materials required for space vehicles performing entry manoeuvres in the atmospheres of Venus, Earth and Mars, is described. The facility with its modular inductive plasma generators allows operation with gases such as carbon dioxide, air, oxygen and nitrogen and was qualified for thermal plasma powers up to 60 kW. Previously developed models for determining plasma properties and plasma source related characteristics enable a maximum plasma power in combination with long operational periods using different operational gases and gas mixtures. This is achieved by an optimization using the optimum operational frequency, a minimization of field losses using very thin plasma tube wall thicknesses and the successful application of MHD effects. Based on the solved cylinder problem for ICPs, a one-dimensional model for radial Lorentz forces and magnetic pressure has been developed. Here, a synthesis of previously published data and works is made where the new algebraic model for the calculation of Lorentz forces and magnetic pressures in an ICP was used and applied to experimental data. In addition, results from the model using the experimental data are shown to be consistent and, in addition, a comparison with a simpler model based on the well-known exponential approach for ICPs showed that the simpler model is covered without fail by the new model. The new model also states that there is a maximum of the Lorentz forces over the damping parameter d/δ (plasma diameter divided by skin depth) which almost corresponds with the position of the maximum plasma power of the cylindric model for ICPs. For the magnetic pressure the position of the maximum pressure is identical to the value for d/δ for the maximum plasma power.


2018 ◽  
Vol 141 (5) ◽  
Author(s):  
Yeshaswini Emmi ◽  
Andreas Fiolitakis ◽  
Manfred Aigner ◽  
Franklin Genin ◽  
Khawar Syed

A new model approach is presented in this work for including convective wall heat losses in the direct quadrature method of moments (DQMoM) approach, which is used here to solve the transport equation of the one-point, one-time joint thermochemical probability density function (PDF). This is of particular interest in the context of designing industrial combustors, where wall heat losses play a crucial role. In the present work, the novel method is derived for the first time and validated against experimental data for the thermal entrance region of a pipe. The impact of varying model-specific boundary conditions is analyzed. It is then used to simulate the turbulent reacting flow of a confined methane jet flame. The simulations are carried out using the DLR in-house computational fluid dynamics code THETA. It is found that the DQMoM approach presented here agrees well with the experimental data and ratifies the use of the new convective wall heat losses model.


2020 ◽  
Vol 198 ◽  
pp. 01030
Author(s):  
Wang Tieli

By analyzing the momentum transfer and velocity both of solid particles and water over the acceleration time of solid particles, as well as interaction mechanism between water and solid particals, a new model is proposed to predict friction loss for setting slurry flow in inclined pipe. The hydraulic gradient formula for inclined pipes summarized by the author is confirmed by a large amount of experimental data. The results show that the deviation between the theoretical value of the model proposed by the author and the measured value is not more than 13.33%, which is the smallest among all reports.


2019 ◽  
Vol 33 (26) ◽  
pp. 1950313
Author(s):  
Li-Na Wang ◽  
Xing-Yu Zhao ◽  
Yi-Neng Huang

The Debye relaxation of dielectric spectroscopy exists extensively in monohydroxy alcohols, and the existing theory of the dielectric strength is obviously inconsistent with the experimental results. In this paper, we propose an Ising model of infinite free-rotating pseudospin chains and get the exact solution of the dielectric strength versus temperature. The model predictions are qualitatively consistent with the experimental results, especially the crossover from the low to the high-temperature Curie–Weiss law. The quantitative comparisons indicate that the model predictions can agree well with the experimental data below 250 K.


Author(s):  
S. Neelakantan ◽  
M. E. Crawford

A new model is developed to predict laterally-averaged film cooling. At the injection location, the near-hole region is leapt over and the injectant is distributed according to an existing jet in cross flow model and experimental data. The subsequent dispersion of the injectant is simulated to reflect the augmented mixing and the 3-dimensionality of the flow field. The new model is calibrated to predict effectiveness and heat transfer using the experimental data bases of Schmidt et al. (1994), Sen et al. (1994), Kohli et al. (1994), and Sinha et al. (1991). The geometries include injection angles of 35° and 55° with compound angles of 0° and 60° and hole spacings of 3 and 6 diameters. The new model yields improved effectiveness predictions over previous 2-D models.


2006 ◽  
Vol 526 ◽  
pp. 13-18 ◽  
Author(s):  
H. Perez ◽  
Antonio Vizan Idoipe ◽  
J. Perez ◽  
J. Labarga

Many investigations have been developed related to precision machining with features in the millimetre scale. In this paper different cutting force models for micromilling are analyzed and compared. A new model based on specific cutting force that also considers run-out errors has been developed. The estimated cutting forces obtained with this model had good agreement with the experimental data. Also, the proposed model allows to be implemented within the machine control for the on-line optimization of the micromilling process.


2000 ◽  
Vol 53 (1-2) ◽  
pp. 37-55 ◽  
Author(s):  
Wim P Cofino ◽  
Ivo H.M van Stokkum ◽  
David E Wells ◽  
Freek Ariese ◽  
Jan-Willem M Wegener ◽  
...  

2009 ◽  
Vol 23 (12) ◽  
pp. 1499-1507
Author(s):  
CUILING ZHANG ◽  
LEI TAN ◽  
KUNYAN ZHU

A new model is proposed to study the effect of mutual interaction revealed in a recent experiment.1 Unlike conventional Hartree–Fock theory, which only studies onset interactions between indistinguishable interacting bosons, our model further includes the mutual interaction between the condensate component and the thermal component. The derived condensate fraction and transition temperature explain the experimental data in a reliable manner.


2011 ◽  
Vol 116 (B11) ◽  
pp. n/a-n/a ◽  
Author(s):  
Y. Bernabé ◽  
M. Zamora ◽  
M. Li ◽  
A. Maineult ◽  
Y. B. Tang

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