I have an airplane and have done a gust response analysis - for a discrete vertical gust. I used the nastran example from chapter 9 section 1. How can I do a side gust analysis - gust 90 degree angle to gravity vector? Can you point me to an example.

Thanks again Sanjay,

My first thought was that I should orient the aero axis from the side ---- then I talked myself out of it – mistakenly. I confused myself into thinking that I had to also re-orient the basic coordinate system. That’s one of the bad things about working by myself.

I have to think through this, but I believe that if I do one run with a vertical gust, and a second run with a side gust, I should be able (by linearity) to construct a load case for a gust at any other angle relative to the flight path. I expect a square edge gust from any direction (of the clock) should work – similarly to the vertical gust case in 9.1. An issue to be determined is whether the gust needs to be reversed as for the vertical case, or whether some other shape is needed.

“Around the clock” gust loads is standard analysis for aircraft certification. I have used those codes, but have not created a load case myself until now. Using Nastran to do all the work is what I was hoping to do.

Thanks, I am going to ponder this a little more.

scott

Thanks again Sanjay,

My first thought was that I should orient the aero axis from the side ---- then I talked myself out of it – mistakenly. I confused myself into thinking that I had to also re-orient the basic coordinate system. That’s one of the bad things about working by myself.

I have to think through this, but I believe that if I do one run with a vertical gust, and a second run with a side gust, I should be able (by linearity) to construct a load case for a gust at any other angle relative to the flight path. I expect a square edge gust from any direction (of the clock) should work – similarly to the vertical gust case in 9.1. An issue to be determined is whether the gust needs to be reversed as for the vertical case, or whether some other shape is needed.

“Around the clock” gust loads is standard analysis for aircraft certification. I have used those codes, but have not created a load case myself until now. Using Nastran to do all the work is what I was hoping to do.

Thanks, I am going to ponder this a little more.

scott