Drogue Descent Rate in OR

[davdue]

I am using OR to design my first dual deploy rocket. I am building it for L2 but will also fly it on an AeroTech I211W and then use the J275W for cert. My question is how do you plot or find the descent rate for the droque part. It gives me the main descent rate but I haven't found the drogue descent rate?

 

[mikeyd]

Does it show it when you plot your flight? Here is what one I have setup shows. According to the graph. Looks like about 60-70 fps on drouge, then 17 is what is shows for Main. If you export to a CSV file, you can look at each data point.



View attachment 8 in crayon m900.xls

View attachment 8in CrayonLoki.ork

 

[davdue]

Sorry I should have attached my OR file. Here it is. I guess I don't know how to read the plot because it does show the drogue deploy. It is attached now. I have 3 different motors selected. A J for L2 cert and a couple I's for more economical launch costs.

View attachment 4 inch Dual Deploy Rocket.ork

 

[mikeyd]

Just looking at the I211, it looks like the drouge is at just under 50fps, it is the blue line in the chart, and it is a negative indication, as it is on the way down. The speed is on the right of the chart. If you export this as a CSV (Coma Seperated Value, you can open it with excel, and it will display the actual estimated values from the data points.





View attachment 4in dd.xls

 

[davdue]

So you determined that by looking at the velocity at the time of main deployment which is the flat line at -50 ft/s between the drogue and the main deployment?

 

[mikeyd]

Basically yes, but you note that the drouge comes out at appogee, and if you look at the all of the exported data, due to appogee being the slowest part, the rate is low, and then builds to the maximum value, allowed by the program, and the size of the chute to weight. Which is just before main deployment. If you look at the screen shot I did of the exported data, you see at the top it was -40, and slowly climbed to about -047.7, and bounced around that, until the main came out. If you compare this to the events on the graph, you can "see" this on the blue line.