This article introduces a methodology for designing the geometry of diffuse-walled radiant enclosures through nonlinear programming. In this application, the enclosure is represented parametrically using B-spline curves, while the radiosity distribution is solved by infinitesimal-area analysis. The enclosure geometry is repeatedly adjusted with a gradientbased minimization algorithm until a nea...

One of the main problems of interval computations is, given a function f(x 1 problem is feasible for linear functions f, but for generic polynomials, it is known to be computationally intractable. Because of that, traditional interval techniques usually compute the enclosure of y, i.e., an interval that contains y. The closer this enclosure to y, the better. It is desirable to describe cases in...

The voltage on a single-turn loop inside an enclosure characterizes the enclosure shielding effectiveness against a lightning insult. In this paper, the maximum induced voltage on a single-turn loop inside an enclosure from lightning coupling to a metal enclosure wall is expressed in terms of two multiplicative factors: (A) the normalized enclosure wall peak penetration ratio (i.e., ratio of th...

─ This paper deals with an impact of receiving antenna placed in a metal enclosure on an electromagnetic field distribution within the enclosure, and thus on its shielding effectiveness. In an experimental setup, a frequently used tool for measuring the electromagnetic field level at certain points within the enclosure is a dipole antenna connected to a measuring instrument via a coaxial cable....

Department of Mechanical Engineering, The Hong Kong Polytechnic University Hung Home, Kowloon, Hong Kong, SAR of China Email address: [email protected]. Abstract This paper examines the influence of the internal resistance of a Helmholtz resonator on the noise control in a small enclosure. The absorptive process mainly occurring within the neck of a Helmholtz resonator provides the resonator w...

in the present study, mixed convection laminar flow around an adiabatic body in a lid-driven enclosure filled with nanofluid using variable thermal conductivity and variable viscosity is numerically investigated. the fluid around the body in the enclosure is a water-based nanofluid containing al2o3 nanoparticles. the vertical enclosure’s walls are maintained at constant cold temperature and the...

The dispersion in photonic crystal fibers likewise conventional optical fibers determines performance of optical systems. Fibers having near-zero dispersion and wideband flat characteristics are considered crucial for applications in both the linear and nonlinear regimes. This paper presents an octagonal photonic crystal fiber design for ultra-flattened chromatic dispersion characteristic and e...