The article is an excellent example of why old references are limited. Research from the early 60's showed that many minimum drag shapes were possible that achieved frontal area Cd's of less than half of what was quoted in this old book. The research then shifted to volumetric drag coefficients, i.e. total drag vs. volume. The work was funded by the Navy and started with towed mine detectors and later shifted to torpedoes.
Given a fixed volume of engine, drive system, fuel, and warhead, practical torpedoes were tested at less than 1/4th the drag of the long shape we are all familiar with. Speed and range surpassed the ability of the sonar to handle the flow noise, and the shapes required total redesign of the torpedo rooms and submarine architecture. Therefore, these shapes were not adopted.
Since the 60's a great deal of R&D and testing has driven the minimum drag of some production air vehicles closer and closer to the theoretical minimum frontal area Cd of less than .02 vs. min drag Reynolds number.
While I have already been chastised for saying something mean about our over-zealous librarian, The difficulty I have with the last several posts is simply that they are nothing more than a huge volume of out-of-date reference material. A HALF CENTURY of progress makes 100% of that article obsolete. I appreciate that the poster is trying to be helpful, but he is not an aerodynamicist and the article creates nothing but misunderstanding of current knowledge and the perpetuation of 50-year old myths.
One might as well read about "the ether" that radio waves and light were supposed to propagate through. We know better now, and accurate understanding takes no more than a high school physics understanding as long as the explanation is from our current knowledge base.
