arXiv: Classical Physics最新文献_第7页

Liouville’s theorem from the principle of maximum caliber in phase space 由相空间最大口径原理导出的刘维尔定理

arXiv: Classical Physics Pub Date : 2016-02-08 DOI: 10.1063/1.4959044

Diego L. Gonz'alez, S. Davis

引用次数: 3

A Comparison between Abraham and Minkowski Momenta 亚伯拉罕动量与闵可夫斯基动量之比较

arXiv: Classical Physics Pub Date : 2016-02-05 DOI: 10.4236/jmp.2016.73032

M. Testa

引用次数: 10

Time-domain numerical modeling of brass instruments including nonlinear wave propagation, viscothermal losses, and lips vibration 铜管乐器的时域数值模拟，包括非线性波传播，粘热损失，和嘴唇振动

arXiv: Classical Physics Pub Date : 2015-11-13 DOI: 10.3813/AAA.919038

H. Berjamin, B. Lombard, C. Vergez, E. Cottanceau

{"title":"Time-domain numerical modeling of brass instruments including nonlinear wave propagation, viscothermal losses, and lips vibration","authors":"H. Berjamin, B. Lombard, C. Vergez, E. Cottanceau","doi":"10.3813/AAA.919038","DOIUrl":"https://doi.org/10.3813/AAA.919038","url":null,"abstract":"A time-domain numerical modeling of brass instruments is proposed. On one hand, outgoing and incoming waves in the resonator are described by the Menguy-Gilbert model, which incorporates three key issues: nonlinear wave propagation, viscothermal losses, and a variable section. The non-linear propagation is simulated by a TVD scheme well-suited to non-smooth waves. The fractional derivatives induced by the viscothermal losses are replaced by a set of local-in-time memory variables. A splitting strategy is followed to couple optimally these dedicated methods. On the other hand, the exciter is described by a one-mass model for the lips. The Newmark method is used to integrate the nonlinear ordinary differential equation so-obtained. At each time step, a coupling is performed between the pressure in the tube and the displacement of the lips. Finally, an extensive set of validation tests is successfully completed. In particular, self-sustained oscillations of the lips are simulated by taking into account the nonlinear wave propagation in the tube. Simulations clearly indicate that the nonlinear wave propagation has a major influence on the timbre of the sound, as expected. Moreover, simulations also highlight an influence on playing frequencies, time envelopes and on the playability of the low frequencies in the case of a variable lips tension.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"2 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131001216","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 17

Dynamical pressure for fluid mixtures with several temperatures 具有不同温度的流体混合物的动压力

arXiv: Classical Physics Pub Date : 2015-10-19 DOI: 10.1051/meca/2009052

H. Gouin, T. Ruggeri

引用次数: 0

Analytical determination of the attack transient in a clarinet with time-varying blowing pressure 时变吹风压力下单簧管冲击瞬态的分析测定

arXiv: Classical Physics Pub Date : 2015-10-16 DOI: 10.3813/AAA.918897

André Almeida, B. Bergeot, C. Vergez, B. Gazengel

{"title":"Analytical determination of the attack transient in a clarinet with time-varying blowing pressure","authors":"André Almeida, B. Bergeot, C. Vergez, B. Gazengel","doi":"10.3813/AAA.918897","DOIUrl":"https://doi.org/10.3813/AAA.918897","url":null,"abstract":"This article uses a basic model of a reed instrument , known as the lossless Raman model, to determine analytically the envelope of the sound produced by the clarinet when the mouth pressure is increased gradually to start a note from silence. Using results from dynamic bifur-cation theory, a prediction of the amplitude of the sound as a function of time is given based on a few parameters quantifying the time evolution of mouth pressure. As in previous uses of this model, the predictions are expected to be qualitatively consistent with simulations using the Raman model, and observations of real instruments. Model simulations for slowly variable parameters require very high precisions of computation. Similarly, any real system, even if close to the model would be affected by noise. In order to describe the influence of noise, a modified model is developed that includes a stochastic variation of the parameters. Both ideal and stochastic models are shown to attain a minimal amplitude at the static oscillation threshold. Beyond this point, the amplitude of the oscillations increases exponentially, although some time is required before the oscillations can be observed at the '' dynamic oscillation threshold ''. The effect of a sudden interruption of the growth of the mouth pressure is also studied, showing that it usually triggers a faster growth of the oscillations.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-10-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"134026132","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 2

On solutions of Maxwell's equations with dipole sources over a thin conducting film 导电薄膜上偶极源麦克斯韦方程组的解

arXiv: Classical Physics Pub Date : 2015-09-14 DOI: 10.1063/1.4945083

D. Margetis, M. Luskin

引用次数: 12

Plane-Wave Propagation in Electromagnetic PQ Medium 电磁PQ介质中的平面波传播

arXiv: Classical Physics Pub Date : 2015-08-25 DOI: 10.2528/PIER15082504

I. Lindell

引用次数: 4

Extend the explanation of transformation optics in metamaterial-modified wireless power transfer system 扩展了变换光学在超材料改进无线电力传输系统中的应用

arXiv: Classical Physics Pub Date : 2015-08-10 DOI: 10.1063/1.4943774

Lin Zhu, Xudong Luo, Hong-ru Ma

引用次数: 8

Classical power and energy relations for macroscopic dipolar continua derived from the microscopic Maxwell equations 由微观麦克斯韦方程组导出宏观偶极连续体的经典功率和能量关系

arXiv: Classical Physics Pub Date : 2015-08-08 DOI: 10.2528/PIERB16081901

A. Yaghjian

{"title":"Classical power and energy relations for macroscopic dipolar continua derived from the microscopic Maxwell equations","authors":"A. Yaghjian","doi":"10.2528/PIERB16081901","DOIUrl":"https://doi.org/10.2528/PIERB16081901","url":null,"abstract":"Positive semi-definite expressions for the time-domain macroscopic energy density in passive, spatially nondispersive, dipolar continua are derived from the underlying microscopic Maxwell equations satisfied by classical models of discrete bound dipolar molecules or inclusions of the material or metamaterial continua. The microscopic derivation reveals two distinct positive semi-definite macroscopic energy expressions, one that applies to diamagnetic continua and another that applies to paramagnetic continua. The diamagnetic dipoles are \"unconditionally passive\" in that their Amperian magnetic dipole moments are zero in the absence of applied fields. The analysis of paramagnetic continua, whose magnetization is caused by the alignment of randomly oriented \"permanent\" Amperian magnetic dipole moments that dominate any induced diamagnetic magnetization, is greatly simplified by first proving that the microscopic power equations for rotating \"permanent\" Amperian magnetic dipoles (which are shown to not satisfy unconditional passivity) reduce effectively to the same power equations obeyed by rotating unconditionally passive magnetic-charge magnetic dipoles. The difference between the macroscopic paramagnetic and diamagnetic energy expressions is equal to a \"hidden energy\" that parallels the hidden momentum often attributed to Amperian magnetic dipoles. The microscopic derivation reveals that this hidden energy is drawn from the reservoir of inductive energy in the initial paramagnetic microscopic Amperian magnetic dipole moments. The macroscopic, positive semi-definite, time-domain energy expressions are applied to lossless bianisotropic media to determine the inequalities obeyed by the frequency-domain bianisotropic constitutive parameters. Subtleties associated with the causality as well as the group and energy-transport velocities for diamagnetic media are discussed.","PeriodicalId":331413,"journal":{"name":"arXiv: Classical Physics","volume":"9 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2015-08-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133178306","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 11

Poisson-Nernst-Planck equations in a ball 球中的泊松-能-普朗克方程

arXiv: Classical Physics Pub Date : 2015-05-07 DOI: 10.1007/978-3-319-76895-3_10

Z. S. J. Cartailler, D. Holcman

引用次数: 2