+1 Excellent piece of analysis, surely must be valuable to Asobo.
I’d like to suggest a couple of refinements:
(Figure 6) - Lift between cloud layer bottom altitude & top altitude:
I agree this is correct in principle but would like to add that usable lift for a glider on a decent thermalling day may extend ~ two-thirds into the height of the cloud. I.e. when I’ve emerged from a cloud climb it’s possible to see the bulk of the cloud mass beneath me, for the cloud I climbed in and the surrounding clouds.
(Figure 7) The ‘slope’ of the thermal with the wind:
This might be just a clarification. IMHO this is a complicated because in a simulator it depends whether the thermal is described in the frame-of-reference of the cloud or the ground. Ultimately, the essential fact is if you’re, say, half way between the ground and cloudbase, then you can circle in the thermal up to cloudbase without requiring huge corrections due to the wind. This could be described as that part of the thermal being vertically under the cloud and drifting with the cloud OR as being sloped relative to the ground. To the second approximation, IF you have to correct your turn while circling in a thermal, then it seems you are more likely to need to do that INTO WIND than in another direction, but this is nothing like continually correcting into wind to compensate for the full wind drifting you out of the thermal. Possibly what you’re doing at that point is picking up a later bubble from the same (fixed) ground source. There is huge subtlety here - the actual upward trajectory of the thermal to the cloud drifting with the wind isn’t exactly known. A ‘snapshot’ that suggests the thermal is a straight diagonal line from the heat source on the ground to the base of cloud is probably not quite right as at normal cruising altitudes (e.g. half cloudbase to cloudbase) the thermal is more directly under the cloud than a diagonal line would suggest.
(Figure 10) “Earth thermal” vs wind:
I know it’s a bit strange talking about “earth thermals” and “cloud thermals” when in RL these are connected, but looking at Fig 10. I’d like to suggest that certainly up to at least 10 knots, thermalling at any height in RL is pretty much unaffected, i.e. if the airmass is going to give you 5 knot climbs, it doesn’t seem to matter if it’s zero wind or 10 knots wind, you can still climb at 5 knots assuming you’ve found the thermal.
Please note my intention for these comments is INCREMENTAL enhancements to the excellent analysis above, i.e. refinements of a couple of the concepts described. IMHO in terms of incremental improvement to the current MSFS implementation of thermals the analysis provided by ANRI is excellent.
B21