力学与航天航空工程

工程力学概论论文

题目：力学与航空航天工程*名：**

学号：********** 学院：土木工程与力学学院专业：工程力学

指导老师：**

力学与航天航空工程

费腾

土木工程与力学学院工程力学1501

摘要：航空航天工程是我国的一项最新科学技术的项目，和人们的日常生活以及我国的经济发展紧密相连。人们平时乘坐的飞机，探索外太空时用的火箭和飞船，都是这项工程的成果。而飞行器的制造，力学对其起到了重要的作用。

20世纪初的时候,人们研制出了飞机，空气动力学因此被人们所逐渐重视起来，由此空气动力学得到长足的进步。人们也逐渐发现很多问题并且逐一解决，人们开始研究飞行器四周的受力情况和飞行器周围的空气流动情况，这就大大促进了流体力学的发展。20世纪初，儒科夫斯基、恰普雷金、普朗特等研究人员,开创了最早的机翼理论,解释了为何机翼会受到举力,飞机是如何被举上天空。人们通过机翼理论对无粘流体的理论有了新的认识,认为它对于指导工程设计存在着的重大作用。

湍流是流体力学中最困难的问题之一，曾经吸引了众多人从事研究。例如普朗特，柯莫戈罗夫,兰道（Landau）等人。经过一代代人们的研究，人类对于湍流现象已经有了一定的了解。也逐渐探索到了一些解决的方法。

湍流是流体的一种流动状态。当流速很小的时候，流体分层流动，互不混合，称为层疏，也称为稳流或片流；逐渐增加流速，流体的流线开始出现波浪状的摆动，摆动的频率及振幅随流速的增加而增加，此种流况称为过渡流；当流速增加到很大时，流线不再清楚可辨，流场中有许多小漩涡，层流被破坏，相邻流层间不但有动滑，还有混合。这时的流体作不规则运动，有垂直于流管轴线方向的分速度产生，这种运动称为湍流，又称为乱流、扰流或紊流。

关键词：航空航天；力学

Abstract: aerospace engineering is a comprehensive project of the

latest science and technology, and China's economic development and people's lives are closely related. Aerospace engineering plays a very important role in the exploration of mineral deposits and weather forecast.

In the early twentieth Century, the emergence of the aircraft greatly promoted the development of aerodynamics, the development of the aviation industry, expected to be able to reveal the pressure distribution around the aircraft, the aircraft's stress situation and resistance and other issues. This has promoted the development of the experimental and theoretical analysis of fluid mechanics. At the beginning of the 20th century, the JOUKOWSKY, Chaplygin, Prandtl PL is representative of the researchers, creating a to the inviscid incompressible fluid potential flow theory based on airfoil theory, clarifies the wing how will be lifting, so that air can support heavy aircraft in the sky. The correctness of wing theory makes it a new understanding of the theory of non viscous fluid, and it is certain that it guides the engineering design.

The most difficult phenomenon in fluid mechanics is turbulence, and turbulence is the most fundamental problem, which has attracted many people to study. Such as: Prandtl, Co Mo Gore Rolf, Landau (Landau) etc.. After many generations of research, has experienced the phenomenological theory, statistical theory, model theory until today's direct numerical simulation and other stages, the understanding of this problem has been greatly deepened.

Turbulent flow is a flow state of the fluid. When the flow rate is very small, stratified flow, mixing, said thin layer, also called the steady flow or flow; gradually increase the flow rate, fluid streamlines began to appear wavy swing, swing frequency and amplitude increases with the increase of flow velocity, such flow conditions