喷气发动机的结构及原理（The structure and principle of a jet engine）.doc

喷气发动机的结构及原理（The structure and principle of a jet engine） The structure and principle of a jet engine Active content Science Lecture: the structure and principles of jet engines Active purpose 1, make students deepen the understanding and application of the structure and basic working process of internal combustion engine 2, make students realize that modern cutting-edge technology originates from the basic knowledge of physics they are learning 3, stimulate students to learn science, with the enthusiasm of science, to cultivate their observation and analysis ability and invention creation consciousness Event preparation Teachers draw up the structure, the principle diagram, the film, the students read physics books second, the third chapter of the content Active process 1, the question raised The students in the class have learned some knowledge of the internal combustion engine, internal combustion engine that is based on the improvement and development of the steam engine, please recall sitting students to answer three questions like this (projector displayed). Question 1: what improvements did the internal combustion engine make on the basis of the steam engine? Summary: the most prominent is the boiler with lightweight cylinder instead of heavy, doing so can make the fuel burn more fully, on the other hand, the loss of heat of combustion products is reduced greatly, improve work efficiency, and compact structure. Question 2: diesel engine was invented in 16 years after the birth of gasoline engine. How has it been improved? Sum up: the most important improvement is to replace the spark plug with the fuel injector, so that the fuel in the cylinder smoothly and fully combustion, compression more thorough, greater work, so the efficiency of diesel engines higher than gasoline engines Question 3: what are the unsatisfactory aspects of internal combustion engines from the point of view of energy loss? Sum up: from the point of view of energy loss, both gasoline engin