化学工程与工艺专业英语翻译

what do we mean by transport phenomena ?

Transport phenomena is the collective name given to the systematic and integrated study of three classical areas of engineering science : (i) energy or heat transport ,(ii) mass transport or diffusion ,and (iii) momentum transport or fluid dynamics . 传递现象是工程科学三个典型领域系统性和综合性研究的总称：能量或热量传递，质量传递或扩散，以及动量传递或流体力学。Of course , heat and mass transport occur frequently in fluids , and for this reason some engineering educators prefer to includes these processes in their treatment of fluid mechanics . 当然，热量和质量传递在流体中经常发生，正因如此一些工程教育家喜欢把这些过程包含在流体力学的范畴内。Since transport phenomena also includes heat conduction and diffusion in solids , however , the subject is actually of wider scope than fluid mechanics. 由于传递现象也包括固体中的热传导和扩散，因此，传递现象实际上比流体力学的领域更广。It is also distinguished from fluid mechanics in that the study of transport phenomena make use of the similarities between the equations used to describe the processes of heat,mass,and momentum transport. 传递现象的研究充分利用描述传热，传质，动量传递过程的方程间的相似性，这也区别于流体力学。These analogies,as they are usually called, can often be related to similarities in the physical mechanisms whereby the transport takes place. 这些类推(通常被这么叫)常常可以与传递现象发生的物理机制间的相似性关联起来。As a consequence,an understanding of one transport process can readily lead to an understanding of other processes. 因此，一个传递过程的理解能够容易促使其他过程的理解。Moreover,if the differential equations and boundary conditions are the same,a solution need be obtained for only one of the processes since by changing the nomenclature that solution can be used to obtain the solution for any other transport process. 而且，如果微分方程和边界条件是一样的，只需获得一个传递过程的解决方案即可，因为通过改变名称就可以用来获得其他任何传递过程的解决方案。

It must be emphasized , however, that while there are similarities between the transport processes, there are also important differences , especially between the transport of momentum (a vector ) and that of heat or mass (scalars ). 必须强调,虽然有相似之处,也有传递过程之间的差异,尤其重要的是运输动量(矢量)和热或质量(标量). Nevertheless, a systematic study of the similarities between the transport processes makes it easier to identify and understand the differences between them. 然而,系统地研究了相似性传递过程之间的相似性,使它更容易识别和理解它们之间的差别。

1．How We Approach the Subject 怎么研究传递过程？

In order to demonstrate the analogies between the transport processes , we will study each of the process in parallel-instead of studying momentum transport first , then energy transport , and finally mass transport. 为了找出传递过程间的相似性，我们将同时研究每一种传递过程——取代先研究动量传递，再传热，最后传质的方法。Besides promoting understanding , there is another pedagogical reason for not using the serial approach that is used in other textbooks : of the three processes, the concepts and equations involved in the study of momentum transport are the most difficult for the beginner to understand and to use . 除了促进理解之外，对于不使用在其他教科书里用到的顺序法还有另一个教学的原因：在三个过程中，包含在动量传递研究中的概念和方程对初学者来说是最难以理解并使用。Because it is impossible to cover heat and mass transport thoroughly without prior knowledge of momentum transport ,one is forced under the serial approach to take up the most difficult subject (momentum transport) first . 因为在不具有有关动量传递的知识前提下一个人不可能完全理解传热和传质，在顺序法的情况下他就被迫先研究最难的课程即动量传递。On the other hand ,if the subjects are studied in parallel , momentum transport becomes more understandable by reference to the familiar subject of heat transport. 另一方面，如果课程同时被研究，通过参照有关传热的熟悉课程动量传递就变得更好理解。Furthermore,the parallel treatment makes it possible to study the simpler the physical processes that are occurring rather than the mathematical procedures and representations. 而且，平行研究法可以先研究较为简单的概念，再深入到较难和较抽象的概念。我们可以先强调所发生的物理过程而不是数学性步骤和描述。For example ，we will study one-dimensional transport phenomena first because equations instead of partial requiring vector notation and we can often use ordinary differential equations instead of partial differential equations ,which are harder to solve . 例如，我们将先研究一维传递现象，因为它在不要求矢量标注下就可以被解决，并且我们常常可以使用普通的微分方程代替难以解决的偏微分方程。This procedure is also justified by the fact that many of the practical problems of transport phenomena can be solved by one-dimensional models. 加上传递现象的许多