Dev Log Week 2024-46: Back to school

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In week 46 I had to get a couple of important backend things out of the way:

Firstly, some owners of private game worlds had requested that we change the billing period from the current 30 days to actual months. The reason being that many groups of players who share a game world have to coordinate their internal payment schedules to have all the money collected once the due date comes up. With a 30 day billing period, that date shifts every month, which complicates things. So I got that sorted.

Secondly, I phased out our payment processors for prepayment and online bank transfers in favor of one that we’ve already been using for card payments (namely Stripe). But I don’t have to repeat myself here…you can find out all there is to know about this on the blog.

But the most important topic of the week was Aircraft Performance…again. After I more or less shelved my curve fitting ideas (see last week’s devlog) I went on to apply my existing formulas to a few more types to see how well they match the official specs. And while the fits are still far better than what we’ve ever had before, there still seem to be some logical issues that make me suspect my approximations are missing some important input parameters or simplifying things that shouldn’t be simplified.

So because I had a Sunday to myself and didn’t want to “work” out of principle, I sat down to go “back to school”, so-to-speak: I got me a few books on aeronautical engineering and started reading up on the theory behind all of this. For AS, what matters isn’t perfect precision, but plausibility. And my hopes are that when I find and understand the most relevant underlying principles and their inputs, I will find plausible approximations that work well enough in the context of the game. The coming weeks will show how this turns out :smiley:

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Have you looked into the ’ General Aviation Aircraft Design: Applied Methods and Procedures’ from Snorri Gudmundsson? It’s a pretty good book for performance analysis, and it has different analysis methods based on how complex you want it to be.

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Didn’t have that one on my list. I’ll check it out…thanks a lot!

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This one seems to be the corresponding book for commercial airliners: Commercial Airplane Design Principles | ScienceDirect

Your recommendation seems to be focused on GA. Which probably doesn’t change the general principles, but you rarely see a turbofan on a Piper :joy:

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Performance data doesn’t change based on prop or jet. (don’t be misled by the title of the book :grinning:) You know, drag is drag, lift is lift, braking is braking. There are also jet examples in the book. E.g., the book has take-off formulations for both general cases (for jet, prop, anything) or a formulation better used for props. You can apply the same formula across the board if the formula is stated generic.

The book is for the preliminary design of the aircraft. It has a bit more info which can be better used for GAs, but you probably don’t need these additional details anyway for your usage, assuming you are not designing Martin 737 or Martin 320 anyway :crazy_face:. I know people use that book for prelim design class for the jet also.

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Frankly, at the moment I am merely trying to “understand” things, including any differences between jets and props, if any. Just so I have a better intuition what method to use when reverse-engineering input parameters from the limited information we have available.