The paper presents noise reduction (NR) of spiral ducts as a result of computational modeling of acoustic wave propagation. Three-dimensional models were created with the finite element method in COMSOL Multiphysics version 3.3. Nine models of spiral ducts with 1-9 spiral leads were considered. Time-harmonic analysis was used to predict NR, which was shown in spectral and interval frequency ban...

A quasi-one-dimensional approach is presented to analyze three-pass mufflers with perforated elements using numerical decoupling. The approach is further developed to include mufflers with ducts extended into the end cavities. Theoretical predictions are compared with experiments for three different muffler configurations, one fabricated and two commercially available mufflers, and shown to agr...

using of nanofluids and ducts with corrugated walls are both supposed to enhance heat transfer, by increasing the heat transfer fluid conductivity and the heat transfer area respectively. use of a diverging duct with a jet at inlet section may further increase heat transfer by creating recirculation zones inside the duct. in this work two-dimensional incompressible laminar flow of a nanofluid e...

We consider the influence of transverse confinement on instability properties velocity and density distributions reminiscent those pertaining to exchange flows in stratified inclined ducts, such as recent experiment Lefauve et al. (J. Fluid Mech. 848, 508-544, 2018). Using a normal mode streamwise temporal expansion for ducts with various aspect ratios $B$ non-trivial profiles, we calculate two...

Sequences of parameterized Hermite curves following with their endpoints along two guide rails are used to create “transparent” surfaces and tubular sculptures. This parameterized set-up allows modeling a wide variety of shapes in a natural way by just changing a few parameters. Potential applications range from mathematical visualization models to architecture.

Structural analysis and design of efficient pressurized fuselage configurations for the advanced BlendedWing-Body (BWB) flight vehicle is a challenging problem. Unlike a conventional cylindrical pressurized fuselage, stress level in a box type BWB fuselage is an order of magnitude higher, because internal pressure primarily results in bending stress instead of skin-membrane stress. In addition,...

Cylindrical ducts with axial mean temperature gradient and flows are typical elements in rocket engines, can combustors, afterburners. Accurate analytical solutions for the acoustic waves of longitudinal transverse modes within these significantly improve performance low order network models analyses behaviours combustion instabilities kinds ducts. Here, we derive an wave equation as a function...