Aren't all V-speeds indicated rather than true?
Many aircraft Vnes are IAS but Vans are all TAS because of flutter concerns. This is the concern with turboed Vans designs.
Aren't all V-speeds indicated rather than true?
Turbos can be very reliable. There is almost no diesel applications left that do not include a turbo. Aircraft turbo-charging is closer related to diesel applications than racing car applications. Sub milisecond throttle response is not required so the turbine can be a larger diameter and therefore rotate at much more reasonable RPM's and allow dependability like diesel applications.
I have wondered if EGR could not be used effectively in aircraft. It would allow control of Turbine Inlet Temperature and allow continuous boost without worrying about detention as much. This is used in for this purpose in modern auto control systems.
Bob Parry
Anybody knows if an GVT (Ground Vibration Test) has been performed on any RVs ?
Aeroelastic divergence (flutter) analysis for the main wings was performed by Latoni, Inc., in Vero
Beach, Florida. In preparation for the analysis, ground vibration test (GVT) was conducted in
North Plains, Oregon. The test subjects included a wing with an empty fuel cell and repeated data
collection with a full fuel cell. The data obtained from the GVT formed the basis of the flutter
analysis.
Wing flutter analysis found no flutter within the aircraft's flight envelope. The analysis
included a simulated failure of the aileron control rod.
Horizontal tail flutter analysis found no flutter within the aircraft's flight envelope. The
analysis included balanced and unbalanced conditions, as well as fixed stick and free stick modes.
Elevator trim tab flutter analysis found no flutter within the aircraft's flight envelope.
The report concluded that: "The RV-8 aircraft was shown to be free from flutter to speeds above its
design envelope with the amount of balance weights provided by the manufacturer on all control
surfaces."
My opinion is that your resale value will be degraded. It is almost like saying I will build a custom two bedroom, 1 bath house because it is cheaper and all I need. That is fine but find another person who wants the same.
I'm no aerodynamacist but wouldn't it make sense to relate flutter to IAS? After all IAS is what the airframe "sees" in terms of the atmosphere as the ASI reads the guage pressure for the particular air conditions experienced at the time. Similar to how density altitude is what the airframe sees and determines lift produced at various angle of attacks, airspeeds, etc.
Of couse TAS and IAS are directly related - for one set of air pressures, temperatures, dew points, etc.....
My question is this; Will the standard mount, cowl etc. work with the 0-390 or will some custom work be required? How about the spinner?
What is to be gained? Payload! at 2700# and 210hp even with a fixed pitch prop takeoff performance should be at least as good as a Grumman Tiger, maybe better, based on very similar power and wing loading. But I figure I could save about 100# over a six cylinder.
So, can anyone see any downside to this not mentioned above in this thread? And have I missed any other particularly pertinent threads on this question? And what would Van say?
I have 320 hrs on my super charged renesis. About 210-220 hp. Full fuel, two adults and baggage performance is close to vans 210 hp numbers. Add a passenger in 90F OAT and climb performance is poor but way better than a typical spam can. Love the 93 oct pump gas even with 10% ethanol.
RV10. N416AS. (Working on turbo swap)
I'd be happy to see either methods work. Incidentally, that 200hp at 16,000 feet will get you more like 180 KTAS (208 SMPH), resulting in overall better economy and block times.
I use the same kind of gas in my IO 540 and just like all the avgas burners, I run 170kts at 10,000 feet on 11GPH sipping 91Octane E10.Love the 93 oct pump gas even with 10% ethanol.