专业英语小测验1.ppt

You should fill in these blanks based on your text: 1 、________is that science which seeks to predict the energy transfer which may take place between material bodies as a result of a temperature difference. 2 、 Most readers will be familiar with the terms used to denote the three modes of heat transfer:____________, ____________, and______________. what’s the Chinese mean of the following words or expressions: 3 、polyatomic _______________ 4 、subzero _______________ 5 、 shell-and-tube heat exchanger _______________ 6 、 cross-flow _______________ 1.As an example of the different kinds of problems which are treated by thermodynamics and heat transfer， consider the cooling of a hot steel bar which is placed in a pail of water. 2.We say that the energy is transferred by conduction and that the heat transfer rate per unit area is proportional to the normal temperature gradient. 3. However， if the temperature of the solid is changing with time， or if there are heat sources or sinks within the solid， the situation is more complex. 4. When the pressure of the gas becomes of the order of its critical pressure or， more generally， when non－ideal－gas behavior is encountered， other sources must be consulted for thermal－conductivity data. 5.In view of the foregoing discussion, one may anticipate that convection heat transfer will have a dependence on the viscosity of the fluid in addition to its dependence on the thermal properties of the fluid (thermal conductivity, specific heat, density). 6. The SI system also specifies standard multiples to be used to conserve space when numerical values are expressed. 7. There are many ways to approach a solution and the assumption is made that the reader is “computer literate” and can handle the solution once a basic algorithm is laid out. 8. A dimension is a physical variable used to specify the behavior or nature of a particular system. * * *