## 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 amplication 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…...