Herminio Herrera

Hi everyone Working on obtaining CL Cm polars for the real ASK21 Horizontal Stab (Plane design shown in attached image) i defined two T1-LLT analysis both with all same parameters except Ref. Dimension. But the polars drawn by xflr5 v6.47 are exactly the same ( i attach images with both analysis parameters and both analysis polars), so i do not know either i am not using well the User Defined Ref. Dimensions option for the analysis definition (most likely), or xflr5 V6.47 has a bug. I will appreciate...

Hi Jochen .... "I Only know i know almost nothing " jajajaja. Thank you for giving me light once again, I was in a stupid mental loop. So now XFLR5 Alpha concept is cristal clear and also Tilt Angle concept aswell right away. Kind Regards Herminio Herrera from Madrid.

Hi Jochen ... thank you very much for your quick response .... and your challenge is very wellcome, but please be merciful with me ... by now probably you already have noticed that i am only a wrinkled retired engineer (telecomm) and an enthusiastic (not professional) self-taught gliders aerodynamics young student .... said that .... From the literature i have at hand the Alpha is the angle between the main wing foil centerline at root Chord and the airflow... Also the Decalage Angle is the angle...

If this subject has already being commented and answered in this forum .. i do apologize at front. I am working with an ASK21 sailplane project using real measures and specs. Main Wing and Horizontal Stab have a 2 degree difference on their incidences. If I configure a tilt angle of +2 degrees on the Main wing i get different polar results from when i configure a tilt angle of -2 degrees on the Horizontal Stab, as shown in the attached file. So, what should it be the correct way to configure such...

Thank very much Jochen

Hi thank you for your comments ... could then i assume that the almost stright line that Cl vs Alpha shows in the linear analysis up to 9.650 degrees is close to the real one ? And the stall happens suddenly at that AoA? -------- Mensaje original --------De: Jochen Guenzel jojo26@users.sourceforge.net Fecha: 28/10/20 17:10 (GMT+01:00) Para: "[xflr5:discussion]" 679396@discussion.xflr5.p.re.sourceforge.net Asunto: [xflr5:discussion] Schleicher ASK21B project ... No able to obtain a stall point in...

Hi Jochen ... thank you for your comments .... in your opinion ... could i assume that the almost straight line for the CL vs Alpha up to 9.650 degrees showed by the VLM2 analysis is close to the real one? ... would the stall suddenly appear at that angle of attack? i never have flown a real ASK21B and not know its stall behaviour ... the stall IAS that is documented in the ASK21B flight manual for a all up weight of 470 kg is 65 kmh and that is very very close to the speed the VLM2 analysis of my...

Hi Jochen ... thank you for your comments .... in your opinion ... could i assume that the almost straight line for the CL vs Alpha up to 9.650 degrees showed by the VLM2 analysis is close to the real one? ... would the stall suddenly appear at that angle of attack? i never have flown a real ASK21B and not know its stall behaviour ... the stall IAS that is documented in the ASK21B flight manual for a all up weight of 470 kg is 65 kmh and that is very very close to the speed the VLM2 analysis of my...