Nonreflecting boundary condition for time-dependent multiple scattering

2007 ◽  
Vol 221 (1) ◽  
pp. 41-62 ◽  
Author(s):  
Marcus J. Grote ◽  
Christoph Kirsch
Keyword(s):  
Boundary Condition ◽  
Multiple Scattering ◽  
Time Dependent ◽  
Nonreflecting Boundary Condition

An exact non reflecting boundary condition for 2D time-dependent wave equation problems

Wave Motion ◽  
2014 ◽  
Vol 51 (1) ◽  
pp. 168-192 ◽  
Author(s):  
Silvia Falletta ◽  
Giovanni Monegato
Keyword(s):  
Boundary Condition ◽  
Wave Equation ◽  
Time Dependent

scholarly journals Integral Sentences and Numerical Comparative Calculations for the Validity of the Dispersion Model for Air Pollutants AUSTAL2000

2020 ◽  
Author(s):  
Schenk Rainer
Keyword(s):  
Boundary Condition ◽  
Air Pollutants ◽  
Dispersion Model ◽  
Health And Safety ◽  
Time Dependent ◽  
Research Report ◽  
Federal Republic Of Germany ◽  
General Validity ◽  
Systems Research ◽  
Simulation Results

Abstract *Background: From the authors, Janicke U, Janicke L (2002). Entwicklung eines Modellgestützten Beurteilungssystems für den Anlagenbezogenen Immissionsschutz. IBJanicke Dunum, a dispersion model for air pollutants is being developed under the name AUSTAL2000. This is declared binding in the Federal Republic of Germany. For example, Schenk R (2018b) Deposition Mans Storage And Not Loss. Environmental Systems Research: 16: p. 1-14, it is demonstrated by differential considerations that this model is not validated and is of little use. Following inquiries from various administrative offices and offices to the authors of AUSTAL, Tukenmüller A (2016) Äquivalenz der Referenzlösungen von Schenk und Janicke. Abhandlung Umweltbundesamt Dessau-Rosslau, S: 1 – 5, referenced. Equivalence to all reference solutions according to Schenk (2018b) would have been demonstrated there, which is why the validity of AUSTAL should not be questioned.In addition, the criticism of AUSTAL would only have dealt with differential approaches.This evidence would also not be sufficient to question the time-dependent simulation results of the AUSTAL authors.The validity of AUSTAL cannot be questioned because it is a further development of the so-called “mother model” LASAT, which begins with the research report, Axenfeld F, Janicke L, Münch J (1984) Entwicklung eines Modells zur Berechnung des Staubniederschlages. Umweltforschungsplan des Bundesministers des Innern Luftreinhaltung, Forschungsbericht 104 02 562, Dornier System GmbH Friedrichshafen, Forschungsbericht 1004 02 562, developed as part of a large number of funding projects and has been positively assessed several times by the highest environmental authority in Germany. The use of Berljand's boundary condition in Schenk (2018b) would be inadmissible and wrong. Instead, the Janicke convention would have been valid. Differential considerations alone would also not be enough to doubt the validity of AUSTAL.*Results: Because the validity of the Berljand boundary condition is questioned, its general validity is demonstrated in the present work. To complete all of the evidence, the author of this work also deals with the development of integral sentences, which allows the violation of the main and conservation laws for all individual cases of the reference solutions to spread, sedimentation, deposition and homogeneity to be checked differentially and integrally. The AUSTAL authors provide flat-rate simulation results for all reference solutions. Time series over 10 days would have been expected. The emissions would have been completed in the first hour of the first day. As a result of the recalculations, however, the author of this article comes to the conclusion that these statements are simply inventions by the AUSTAL authors. The calculations also confirm that the AUSTAL authors, contrary to all assurances, did not consider sources at great heights. All homogeneity tests prove to be trivial cases, which can be compared to filling any container with different media. The so-called “parent model” LASAT is supposed to serve for the validity of the AUSTAL dispersion model. In order to find out more about the beginnings of these questionable model developments, the author of this article also deals with the history of the AUSTAL and contrasts it with elite self-portrayals.*Conclusion: The author of this article can prove not only with differential considerations that AUSTAL is not validated. This evidence can also be provided using valid integral sentences. The authors of the AUSTAL were also unable to perform time-dependent simulations. AUSTAL is not validated and is not suitable for the calculation of dispersion, sedimentation, deposition and homogeneity. Statements relevant to health and safety, such as Security analyzes, hazard prevention plans and immission forecasts are to be checked with physically based model developments. Insofar as they can be traced back to the validity of the AUSTAL reference solutions, court decisions are also affected.

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