Most helpful critical review
5 of 5 people found the following review helpful
Basic technical level, diagrams not so good
on 15 December 2009
I am studying 3rd year MEng so I have learnt some thermodynamics and fluid mechanics which are touched on in this book.
Also, I have only read through about a third of the book so far so bear that in mind.
However, so far from what I see, I am very glad that the author includes quite a good number of diagrams of jet engines (nothing is more helpful in this kind of thing than good diagrams, and I have browsed through some other books that seem to be 95% text and 5% diagrams, which is silly so I didn't buy those).
However, it seems to me like rather than having a consistent set of diagrams explaining things in steps, he sort of just found a whole bunch that are vaguely relevant, but not complete, and more often than not, they don't quite go with the text.
For example, there are times when he throws in a random schematic of a really complicated engine when the text is just beginning on classifying the turbofan engine. Although interesting if you know what it is showing, if you are new to all this, it would only serve to confuse you. I feel that those kinds of specific engine schematics should probably be kept until a little later! But of course, that's just my opinion.
Furthermore, what I think is a diagramatical mistake:
When explaining thrust and the conservation of momentum equations, he has a diagram illustrating a turbojet engine with a control volume drawn out. The control volume in the diagram suggests that the horizontal exit boundary includes only the exit nozzle (with smaller area than the inlet, higher velocity and a different pressure), but then when he goes through the math, he includes the area around the nozzle at ambient pressure but not the momentum of this ambient air.
Since I am revising this stuff at the moment and was hoping that this would all easily make sense to me, but I got confused as to whether he was or was not supposed to include the air around the nozzle. I suspect he should since this air exerts a pressure on the engine casing. He is probably right in his analysis, but I really would have liked him to explain that step a bit more. Seems too much like hand waving to me.
And then a real bone headed mistake:
Page 42 says that the table 2-1 should be about derived units of measurement like the Newton, Joule, Watt and Pascal which it is. But then on page 43, it says to look at table 2-1 for imperial-metric conversion. But table 2-1 mentions nothing about converting to imperial!
I assume it should say Table 2-2 and have another table with conversions but this table is nowhere to be found.
Then again, I'm only a student! So the mistakes I supposedly spotted may be my mistake! If so, please forgive me.
Bottom line, I think the book is interesting to read if you're into the subject since it is basic enough that almost anyone with A-level math and physics knowledge could understand.
If like me, you are training in general engineering and you are interested in the subject, but they don't teach or examine you on it, it should be good to read. It may serve as a good example of the applications of some of the fluid and thermo stuff you learn.
However, it is not a textbook so don't treat it as such!