Dixon/Hall's "Fluid Mechanics and Thermodynamics of Turbomachinery" full of errors?

Question

Note: This is no homework, but self-study.

I have a thermodynamics and fluid mechanics background and am trying to work through this book in order to get better understanding of turbomachines (especially for compressible flow). The book was praised across the internet as a classic and basically one of the best turbomachinery books out there. I immediately ran into problems and I think the book has errors. I give two examples and hope you can review them. I hope you can point out mistakes on my side, otherwise this would heavily discourage me to further work through the book.

First problem. So I reviewed the topics of chapter 1 and tried to solve the end-of-chapter problems. This is literally the first problem in the book (1a is easy, 1b has the supposed error).

1a. Air flows adiabatically through a long straight horizontal duct, $0.25 \text{ m}$ diameter, at a measured mass flow rate of $40 \text{ kg/s}$. At a particular section along the duct the measured values of static temperature $T = 150 \text{ °C}$ and static pressure $p = 550 \text{ kPa}$. Determine the average velocity of the airflow and its stagnation temperature.

1b. At another station further along the duct, measurements reveal that the static temperature has dropped to $147 \text{ °C}$ as a consequence of wall friction. Determine the average velocity and the static pressure of the airflow at this station. Also determine the change in entropy per unit of mass flow between the two stations. For air assume that $R = 287 \text{ J/kg/K}$ and $\gamma = 1.4$.

Solutions. 1a is simple: $v = \frac{\dot{m}}{\rho\,A} = \frac{\dot{m}\,R\,T}{p\,A} = 179.93 \text{ m/s}$ and $T_0 = T + \frac{v^2}{2\,\frac{\gamma\,R}{\gamma - 1}} = 439.26 \text{ K}$ which matches the book solution. But now for 1b: $h_{01} = h_{02} = \frac{\gamma\,R}{\gamma - 1}\,T_1 + \frac{v_1^2}{2} = \frac{\gamma\,R}{\gamma - 1}\,T_2 + \frac{v_2^2}{2}$ gives $v_2 = \sqrt{2\,\left(h_{01} - \frac{\gamma\,R}{\gamma - 1}\,T_2\right)} = 195.96 \text{ m/s}$ (not even given in the book solution, even though asked), and then $p_2 = \frac{\dot{m}}{v_2\,A}\,R\,T_2 = 501.42 \text{ kPa}$ (this also matches the book solution). Buut now for the entropy we should have, since we are treating this as a perfect gas, $$ \Delta s = \frac{\gamma\,R}{\gamma - 1} \, \ln{\frac{T_2}{T_1}} - R\,\ln{\frac{p_2}{p_1}} \hspace{1cm}\text{ (also given as Eq. (1.31) in the book})$$

But this gives $\Delta s = 19.39 \text{ kJ/(kg K)}$, while the book solution gives $39.24 \text{ kJ/(kg K)}$.

This I miss anything or does the book present a false solution right from the first problem?

Second problem.

This leads to problems in the end-of-chapter problems, but really appears to be a big typo in an important equation. I found it right in chapter two after turning a few pages from the first problem. On page 47 (7th edition) it says: For a compressor, the isentropic efficiency is defined in Chapter 1 and can be written as $$ \text{Eq. (2.10a)} \hspace{1cm} \eta_C = \frac{\Delta h_{0s}}{\Delta h_0} = \frac{((p_{02}/p_{01})^{\gamma / (\gamma -1)} -1)}{\Delta T_0 / T_{01}} $$.

Now ... apparently the exponent is switched around, correct (in my opinion) is $$ (p_{02}/p_{01})^{(\gamma -1) / \gamma} $$ from the isentropic change of state relations.

I would greatly appreciate your opinion on these two examples. I can't really work through a book when I must assume errors in the text. These I just found at first glance and in the first problems I tried, so this is really discouraging. Hope the errors are on my side!

Edit: Third problem On the right, $\alpha_1$ is used twice, one of them needs to be $\alpha_1^{'}$.

Edit: Fourth problem Multiple references in the book, e.g. text references to figures 3.15 to 3.19 are wrong (numbers are wrong, e.g. 3.17 is used for 3.16).

Answer 1

I am the acquisitions editor for this title (but not a copyeditor). Thank you for bringing these potential errors to our attention. Although we at Elsevier, as well as other scientific publishers, try to do all we can to ensure that a textbook is totally accurate, sometimes errors do make it past the copyeditor, typesetter (who is often the introducer of certain types of errors), proofreader or author, and unless we hear about the error from a customer, it might never be caught and addressed. In this case, the original author S. Larry Dixon passed away several years ago and his co-author moved away from the book after working on a couple of editions, so we have not had anyone who could check with any authority on any errors brought to our attention, although with that said, we have only been alerted to a couple of errors since this edition published. We do have a new author who is working on an 8th edition, to be published next year, so I have asked him to check this site and make sure that any true errors you have found are corrected in the new edition, if he has not already come across them himself. It may be too late to make corrections in the 7th edition files at this point, considering when the book published and the fact that a new edition is on the way, but we can at least post errata to the book's companion site until the current edition is put out of print next year.

Answer 2

my answers to your questions above are listed below.

Problem 1. you are correct. I have checked your equations step by step. nothing wrong. thus you are correct with your answers.

Problem 2. you are also correct. it should be (p02/p01)^((γ−1)/γ)

problem 3. you are also correct.

Problem 4. you are also correct. the references should be correctly cited.