The Moody chart first appeared in “Friction Factors for Pipe Flow” by L. F. Moody, ASME Transactions, November, 1944. It describes the pressure drop characteristics of fluids, and is used to calculate pressure drop, or flow rate, or pipe diameter.
Since its first publication, the Moody chart has appeared in virtually every mechanical and chemical engineering handbook, and every mechanical and chemical engineering undergraduate text on fluid flow. Every student in mechanical or chemical engineering is instructed in the use of the Moody chart.
The problem with the Moody chart is that it must be read in an iterative manner if it is used to calculate flow rate or pipe diameter. The chart can be read in a direct manner only if it is used to calculate pressure drop.
To illustrate, if a chart is in the form y/x vs x, the chart must be read in an iterative manner if y is given and x is to be determined. It can be read in a direct manner only if x is given, and y is to be determined.
In the Moody chart:
If the chart is to be used to determine flow rate from information that includes pressure drop and pipe diameter, neither the x coordinate nor the y coordinate can be calculated from the given information. The chart must be read iteratively to determine the x and y coordinates, and the flow rate can then be determined from the value of the x or y coordinate. (Similarly if the pressure drop and flow rate are given, and the pipe diameter is to be determined.)
Only if the chart is used to determine pressure drop can the chart be read directly. In this case, the given information would include flow rate and pipe diameter, from which the x coordinate and the chart parameter could be calculated. Using the calculated values of the x coordinate and the chart parameter, the Moody chart is read directly to determine the y coordinate, from which the pressure drop is then calculated.
The Moody chart can be transformed to a form that is read without iterating. This requires that the chart be transformed so that flow rate, pressure drop, and pipe diameter each appear singly on the axes and the parameter. For example, the chart could be transformed so that the flow rate appears only on the x axis, the pressure drop appears only on the y axis, and the pipe diameter appears only on the chart parameter.
The manner in which the Moody chart is transformed so that it can be read without iterating, and the improved chart that results, are described in A Transformed Moody Chart That Is Read Without Iterating.
1/27/2004 I submitted A Transformed Moody Chart That Is Read Without Iterating dated January 27, 2004 for possible publication to Editor-in-Chief Nicholas P. Chopey, Chemical Engineering.
4/5/2004 Editor Chopey’s e-mail stated that the manuscript was not accepted for publication “because software for fluid flow calculations has become so widely available and widely used”. It may well be that engineers who subscribe to Chemical Engineering generally use software. But if engineers in general are considered, it seems likely that the Moody chart is used far more widely than software.
4/16/2004 I submitted a draft of A Transformed Moody Chart That Is Read Without Iterating for possible presentation at the 2004 ASME International Mechanical Engineering Congress. It was paper number IMECE2004-60213.
7/28/2004 I withdrew the paper from IMECE consideration before a final decision was reached on acceptance/rejection. (I later was told by the session chairman that the paper was going to be accepted.)
From long and painful experience, I felt that any paper with my name on it would be judged unworthy of publication in an ASME or AIChE journal. I decided that, until I could arrange for its publication, I would treat the paper as proprietary information.
8/9/04 I received an e-mail from an assistant editor of the ASME Journal of Fluids Engineering (JFE) who was familiar with my Moody paper, and was aware that I felt that no article of mine would ever be judged suitable for publication in an ASME or AIChE journal. His e-mail stated: “Your IMECE conference paper looks suitable for the JFE and I am encouraging you to submit it to the JFE for consideration.” He also verbally assured me that my paper would be seriously considered for publication in the JFE.
His strong encouragement and assurance that my paper would receive serious consideration are the reasons I submitted the paper to the JFE in spite of my conviction that it would a priori be judged unworthy because I was the author.
8/10/04 I submitted the paper for possible publication to the ASME Journal of Fluids Engineering. (Paper was sent by US mail.)
11/17/2004 I again submitted the paper to the JFE, this time by e-mail. (I had been told that the JFE had not yet received the paper I had mailed on 8/10/04.)
11/30/2004 I received an e-mail from Laurel Murphy, editorial coordinator, JFE. The e-mail stated that Professor Katz (editor of JFE) had read my paper and “he believes that the material does not fall within the scope of the JFE”.
If Professor Katz truly believes that a vastly improved form of the Moody chart does not fall within the scope of the JFE, then I seriously recommend that the scope of the JFE be changed, or its editor be changed.
The e-mail also stated that Professor Katz “suggests your manuscript would be better suited to a civil engineering journal”. I would very much like to hear Professor Katz’s explanation of why he feels an article dealing with fluid flow would be better suited to a civil engineering journal than to the Journal of Fluids Engineering.
11/30/2004 In an e-mail to Lauren Murphy with a copy to Professor Katz, I responded to the JFE rejection. I pointed out that the Moody chart has been an important part of fluids engineering for 60 years, and that it appears in virtually all mechanical and chemical engineering handbooks and fluid flow texts. I also pointed out that the Moody chart was appropriately published in an ASME Journal, and the vastly improved form presented in my article would appropriately be published in the ASME Journal of Fluids Engineering.
12/2/2004 Professor Katz sent me an e-mail stating that he is certain my article “doesn’t make it as archival material”. Also, he claimed that I was angry and rude, and that my comment (that a civil engineering journal is not the proper place for my article) was inappropriate.
12/2/2004 I sent an e-mail to Professor Katz in which I responded to his e-mail of 12/2/04. I pointed out that my e-mails were frank, not rude. And I was disappointed, not angry. Also, my comment about civil engineering journals was innocuous, not inappropriate.
I pointed out that my article does much more than merely transform the Moody chart to a form that is easier to use. It also presents and demonstrates a new way to deal with fluid flow that has nothing to do with friction factor, and it demonstrates that the friction factor concept should be abandoned because it unnecessarily complicates the solution of practical problems. The article utilizes the new engineering, but the new engineering is not mentioned in the article because I wanted the article to stand alone.
I had been invited to speak on the new engineering at Howard University on 12/15/2004. (Professor Katz is employed at Johns Hopkins University, and it is near Howard University.) I invited Professor Katz to my talk. He did not attend. I was disappointed, not surprised.
6/3/2005 I decided that the best course for me was to place much of my work, including A Transformed Moody Chart That Is Read Without Iterating, on a website.