nighthawk2174 Posted January 31, 2021 Share Posted January 31, 2021 7 hours ago, IVAN01rch said: Hey nighthawk, Naturally Cd coefficient can be defined in a several ways. Maybe you dug into these questions and can help me: How do you take into account working engine when you calculate drag coefficient? Do you simply neglect rocket back wall when integrating pressure over the surface to get the drag force? Obviously you do not want to simulate supersonic jet with nozzle all the time. Do you know how it is made in industry or how does ED make it? Cd is mostly a value for engineering applications so it looks logical to separate drag and engine forces. Do you use cross sectional area of the rockets as the reference area in Cd equation? Are you sure everybody use the same value? Do you take into account thermal effects? What ED did? Do you use ideal or real gas models for supersonic cases? What ED did? Obviously rocket has a lot of control surfaces. And it is useless to apply any angle of atack with all control surfaces at 0 angle as it is not a real situation. Do we know any data about control surfaces movement during flight and manouvers? Feel free to share any thoughts about the topic. 1) Currently DCS can't take this effect into account so I didn't even investigate this. 2) Yes, I used the cross section area as seen from the front, this is what most sources I have on the subject did and as such I used this value as well (Cd0 value). 3) Yes 4) Real and unknown but in all probability real iirc ideal gas models start to fall apart quickly as you get to supersonic flow. 5) Not 100% useless as often there is only one set of fins that moves, additionally it'll get you a reasonable lift value if you can't individually model the control surfaces. To get an accurate enough model where it makes a difference you need to model each control surface. Make it so it has an associated lift value based on the current airflow. Currently i'm unsure if DCS does this for the new model and if it does how to adjust these values. In short its good enough for our purposes but for more complex models you would want to take this into account. Link to comment Share on other sites More sharing options...
Hodo Posted February 2, 2021 Share Posted February 2, 2021 I did manage to get a 40km R-27ER kill the other night online. I was at 10km asl going 1150kmh true engaging a F-4 AI flying at 700kts head on. I was impressed. Link to comment Share on other sites More sharing options...
dundun92 Posted February 2, 2021 Share Posted February 2, 2021 ive gotten 50+km ER and ET kills on PvP, apparently people think you can just out crank a 50nm ER from 12km M1.2 Eagle Enthusiast, Fresco Fan. Patiently waiting for the F-15E. Clicky F-15C when? HP Z400 Workstation Intel Xeon W3680 (i7-980X) OC'd to 4.0 GHz, EVGA GTX 1060 6GB SSC Gaming, 24 GB DDR3 RAM, 500GB Crucial MX500 SSD. Thrustmaster T16000M FCS HOTAS, DIY opentrack head-tracking. I upload DCS videos here https://www.youtube.com/channel/UC0-7L3Z5nJ-QUX5M7Dh1pGg Link to comment Share on other sites More sharing options...
GGTharos Posted February 2, 2021 Share Posted February 2, 2021 On 1/31/2021 at 12:04 PM, nighthawk2174 said: 1) Currently DCS can't take this effect into account so I didn't even investigate this. AFAIK the new FM does. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda Link to comment Share on other sites More sharing options...
nighthawk2174 Posted February 2, 2021 Share Posted February 2, 2021 1 hour ago, GGTharos said: AFAIK the new FM does. rog have they specifically said this is a thing? And also for the older stuff though it isn't which is what the R27 is currently on. Link to comment Share on other sites More sharing options...
GGTharos Posted February 2, 2021 Share Posted February 2, 2021 16 minutes ago, nighthawk2174 said: rog have they specifically said this is a thing? And also for the older stuff though it isn't which is what the R27 is currently on. Yes, but IIRC. For the older stuff I think they tried to simulate this by adding thrust, but this causes its own problems. [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda Link to comment Share on other sites More sharing options...
ED Team Маэстро Posted March 14, 2021 ED Team Share Posted March 14, 2021 On 1/15/2021 at 7:11 AM, nighthawk2174 said: Concerning motor on and motor off differences this is what were talking about: it's about a 20-22% difference. Hi, what is the source of chart? Is there any reference area value for it? YouTube Channel Link to comment Share on other sites More sharing options...
nighthawk2174 Posted March 15, 2021 Share Posted March 15, 2021 14 hours ago, Маэстро said: Hi, what is the source of chart? Is there any reference area value for it? Here's a link: https://drive.google.com/file/d/15P5-lvJibw1CypU3IHjMcGVQpEZ5csA6/view?usp=sharing https://drive.google.com/file/d/15LY3J5hyt0a7FB6UsfnXTRPIqcOrVY4z/view?usp=sharing - this one will probably be useful Link to comment Share on other sites More sharing options...
ED Team Маэстро Posted March 15, 2021 ED Team Share Posted March 15, 2021 5 hours ago, nighthawk2174 said: Here's a link: https://drive.google.com/file/d/15P5-lvJibw1CypU3IHjMcGVQpEZ5csA6/view?usp=sharing https://drive.google.com/file/d/15LY3J5hyt0a7FB6UsfnXTRPIqcOrVY4z/view?usp=sharing - this one will probably be useful Thanks! Very interesting! YouTube Channel Link to comment Share on other sites More sharing options...
nighthawk2174 Posted March 15, 2021 Share Posted March 15, 2021 38 minutes ago, Маэстро said: Thanks! Very interesting! Yeah, maybe one day when DCS gets early 60's stuff this would allow for a hyper accurate simulation of the AIM-7D/E-1 Link to comment Share on other sites More sharing options...
GGTharos Posted March 15, 2021 Share Posted March 15, 2021 That missile body is very similar if not the same as the AIM-7F/M/P [sIGPIC][/sIGPIC] Reminder: SAM = Speed Bump :D I used to play flight sims like you, but then I took a slammer to the knee - Yoda Link to comment Share on other sites More sharing options...
nighthawk2174 Posted March 15, 2021 Share Posted March 15, 2021 8 hours ago, GGTharos said: That missile body is very similar if not the same as the AIM-7F/M/P Yes although they did have different nose cones between the F and M which can result in quite noticeable changes in drag. Link to comment Share on other sites More sharing options...
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