دانلود مقاله مروری بر هیدرودینامیک و کارایی شناگری دلفین Review of Dolphin Hydrodynamics and Swimming Performance
everything about dolphins hydrodynamics
دانلود مقاله تطبیق تولید انرژی غیر متمرکز و مصرف محلی: مروری بر سیستمهای انرژی تجدید پذیر با فناوریهای تبدیل و ذخیره Matching decentralized energy production and local consumption: A review of renewable energy systems with conversion and storage technologies
The increasing share of decentralized intermittent renewable energy reinforces the
necessity of balancing local production and consumption. Decentralized energy
systems, powered by renewable energy technologies and incorporating storage and
conversion technologies, are promising options to cope with this challenge. Many
studies have evaluated their potential contributions, but an overview of the statusquo
in both academia and practice is missing. The extant literature lacks a comprehensive
review of the scientific knowledge on decentralized energy systems,
partially attributed to the lack of common terminology. Additionally, it remains
unclear what kind of systems are already implemented today worldwide as they
have not yet been thoroughly analyzed and described. However, pilot projects provide
valuable insights into future applications and operational aspects. To fill these
gaps, an extensive review of the current state of literature and practice is conducted.
To do so, 64 publications and 56 projects were analyzed and an overview is provided
using four criteria: terminology, scope/motivation, application, and technical
configuration. These criteria facilitate the understanding of decentralized energy
systems needed to spur their development and diffusion. Further advancements of
research and practice are discussed. For example, technological learning hinges on
a common terminology and on an identification of optimal technical configurations
per application. There are both avenues for future research.
This article is categorized under:
Energy Systems Analysis > Economics and Policy
Energy Infrastructure > Systems and Infrastructure
Energy and Urban Design > Systems and Infrastructure
Energy Research & Innovation > Systems and Infrastructure
دانلود مقاله تئوری لایه مرزی:یک پارادوکس قرن بیستم؟ LAMINAR BOUNDARY-LAYER THEORY: A 20TH CENTURY PARADOX?
Boundary-layer theory is crucial in understanding why certain phenomena
occur. We start by reviewing steady and unsteady separation from
the viewpoint of classical non-interactive boundary-layer theory. Next,
interactive boundary-layer theory is introduced in the context of unsteady
separation. This discussion leads onto a consideration of large-
Reynolds-number asymptotic instability theory. We emphasise that a
key aspect of boundary-layer theory is the development of singularities
in solutions of the governing equations. This feature, when combined
with the pervasiveness of instabilities, often forces smaller and smaller
scales to be considered. Such a cascade of scales can limit the quantitative
usefulness of solutions. We also note that classical boundarylayer
theory may not always be the large-Reynolds-number limit of the
Navier-Stokes equations. This is because of the possible ampli cation of
short-scale modes, which are initially exponentially small, by a Rayleigh
instability mechanism.
مقاله مدل های جریان آشفته
An Introduction to Turbulence Models Almost all fluid flow which we encounter in daily life is turbulent. Typical examples are flow around (as well as in) cars, aeroplanes and buildings.The boundary layers and the wakes around and after bluff bodies such as cars, aeroplanes and buildings are turbulent. Also the flow and combustion in engines,…...
مقاله مدل های جریان آشفته 2
Turbulence Models and TheirApplication to Complex FlowsR. H. NicholsUniversity of Alabama atBirmingham Some basic knowledge of turbulence and an understanding of how turbulence models are developed can help provide insight into choosing and applying these models to obtain reasonable engineering simulations of turbulent flows. This effort is directed at production users of Computational Fluid Dynamics…...