3D numerical modelling of acoustic horns using the method of fundamental solutions

In the present work, a three-dimensional (3D) formulation based on the method of fundamental solutions (MFS) is applied to the study of acoustic horns. The implemented model follows and extends previous works that only considered two-dimensional and axisymmetric horn configurations. The more realistic case of 3D acoustic horns with symmetry regarding two orthogonal planes is addressed. The use of the domain decomposition technique with two interconnected sub-regions along a continuity boundary is proposed, allowing for the computation of the sound pressure generated by an acoustic horn installed on a rigid screen. In order to reduce the model discretization requirements for these cases, Green’s functions derived with the image source methodology are adopted, automatically accounting for the presence of symmetry conditions. A strategy for the calculation of an optimal position of the virtual sources used by the MFS to define the solution is also used, leading to improved reliability and flexibility of the proposed method. The responses obtained by the developed model are compared to reference solutions, computed by well-established models based on the boundary element method. Additionally, numerically calculated acoustic parameters, such as directivity and beamwidth, are compared with those evaluated experimentally.

Comparative analysis of constructive solutions for thermal insulation by using computer applications in building rehabilitation in Mediterranean climate. The Spanish case

The new Spanish legislation in Energy Saving, similar to European regulation, provides new technical requirements to adequate technical solutions used in integral rehabilitation of existing buildings. The aim of this paper is to present, analyze and discuss the main thermal insulation constructive solutions best suited to a Mediterranean climate, and conclude on their suitability under the legislation in Energy Saving. The proposed methodology is based on the most usual constructive solutions in integral rehabilitation of buildings by analyzing their outstanding design features, by studying its construction details and then by applying the software provided by the Spanish legislation of energy efficiency in buildings. The results of the study evaluate and classify several solutions for façade rehabilitation according to energy efficiency criteria and their suitability for this type of weather, verifying the necessity of using software applications in energy saving for the proper design of constructive solutions in building rehabilitation.

Application of positive guidance at a freeway-to-freeway connector in California; an urban location in Dubuque, Iowa; and a two-lane rural site in Washington State. Final report.

Mode of access: Internet.

Air stripping of aqueous solutions.

Mode of access: Internet.

Energy-efficient commercial buildings : the range of possible solutions and their conceptual differences /

"Work Performed Under Contract No. EG-77-C-01-4042."

Current concepts of positive mental health;

Bibliography: p. 121-126.

Application of positive guidance at a reverse curve/narrow bridge site in Washington state. Final report.

Federal Highway Administration, Demonstration Projects Division, Arlington, Va.

Application of positive guidance at a freeway split in Michigan. Final report.

Federal Highway Administration, Demonstration Projects Division, Washington, D.C.

Examination of the solutions of the Navier-Stokes equations for a class of three-dimensional vortices,

"Contract AF 49(638)-255."

The impurity analysis of americium solutions /

A solution d-c arc method has been developed for the impurity analysis of americium solutions which are from 3-5 Molar in ammonium thiocyanate.

ASNE-API code for installation, proving and operation of positive displacement meters in liquid hydrocarbon service; or, Petroleum P. D. meter code (short title)

At head of title: ... (Tentative)

A differential method for the determination of partial molal heat capacities and specific heats of dilute solutions /

Thesis (Ph.D.)--University of California, Berkeley, 1922.

Application of the hypothesis of dissolved ice to the freezing of water and of dilute solutions.

Hudson, C.S., cl. of 1901.