Bonjour.
La vue de côté de la CP301 montre un profil bas qui fait un pas vers le haut à l'arrière du capotage. Le coin bas de la fuselage (à l'arrière du capotage) est un angle droit.
Je crois que la CP1301 montre un profil qui est continu entre capotage et fuselage; il y a, a chaque côté, un "mur" (max. 5cm de hauteur et 5cm de largeur), verticale à l'intérieur, courbé à l'extérieur; pas d'angle droit.
Est-ce qu'on peut me dire la raison pour ce changement entre CP301 et CP 1301?
Trevor Wilcock
CP 301S Smaragd G-DENS, Angleterre
L'aérodynamique de l'Emeraude
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Trevor WILCOCK
- Brevet de Base
- Messages : 65
- Enregistré le : 13 mai 2005 16:02
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Trevor WILCOCK
- Brevet de Base
- Messages : 65
- Enregistré le : 13 mai 2005 16:02
Bonjour Laurent,
Veuillez pardonner ma pauvre commande de la langue - essayons en anglais!
Please compare the side views of the bottom line of the fuselage of the CP301 and CP1310: ftopic39.html (second message) and ftopic3.html. Directly behind the engine cowling of the CP301, the fuselage bottom line steps upwards while the CP1310 is a smooth line from engine cowling to fuselage. On my CP301S, behind the engine cowling, the fuselage bottom and side form a right-angle. On a CP1310 that I saw last week, a fairing has been added at each side to give a smooth line from cowling to fuselage. This fairing is approximately a quarter-circle in cross-section, vertical on the inside face, but rounded ouside to give a rounded bottom edge to the fuselage rather than a right-angle. It is about 5cm wide at the forward end, tapering rearwards.
I am interested because on my CP301S I sometimes get buffeting of the tailplane which appears to be caused by turbulent flow starting at the inboard leading edge of the left wing, particularly at low power. My suspicion is that cross-flow from the propellor is separating at the right-angle formed by the fuselage side and underside just forward of the wing, and that the fairings on the CP1310 were added to overcome this problem. Do you have any information?
Amicalement,
Trevor Wilcock
Veuillez pardonner ma pauvre commande de la langue - essayons en anglais!
Please compare the side views of the bottom line of the fuselage of the CP301 and CP1310: ftopic39.html (second message) and ftopic3.html. Directly behind the engine cowling of the CP301, the fuselage bottom line steps upwards while the CP1310 is a smooth line from engine cowling to fuselage. On my CP301S, behind the engine cowling, the fuselage bottom and side form a right-angle. On a CP1310 that I saw last week, a fairing has been added at each side to give a smooth line from cowling to fuselage. This fairing is approximately a quarter-circle in cross-section, vertical on the inside face, but rounded ouside to give a rounded bottom edge to the fuselage rather than a right-angle. It is about 5cm wide at the forward end, tapering rearwards.
I am interested because on my CP301S I sometimes get buffeting of the tailplane which appears to be caused by turbulent flow starting at the inboard leading edge of the left wing, particularly at low power. My suspicion is that cross-flow from the propellor is separating at the right-angle formed by the fuselage side and underside just forward of the wing, and that the fairings on the CP1310 were added to overcome this problem. Do you have any information?
Amicalement,
Trevor Wilcock
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Trevor WILCOCK
- Brevet de Base
- Messages : 65
- Enregistré le : 13 mai 2005 16:02
Hello Laurent,
Ca y est! On the CP1310 that I looked at, the difference was provided by the blocks that I described, so that for most of the width of the fuselage below the fuel tank the two designs are identical, it's just the outermost edges that differ. See attachment.
Regards,
Trevor
Ca y est! On the CP1310 that I looked at, the difference was provided by the blocks that I described, so that for most of the width of the fuselage below the fuel tank the two designs are identical, it's just the outermost edges that differ. See attachment.
Regards,
Trevor
- Fichiers joints
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- Cross-section.jpg (3.37 Kio) Vu 5370 fois
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Trevor WILCOCK
- Brevet de Base
- Messages : 65
- Enregistré le : 13 mai 2005 16:02
Hi
Hi there,
Cooling maybee ?!?!?
It may be some kind of vent allowing the air to flow out of the engine compartment.
In order to cool the engine, there must be an airflow around it. And in order to have an airflow there must be a way in "front air intake" and a way out "that kind of vent"... maybe.
Cette solution est peut etre déstinée à faciliter la circulation d'air dans le compartiment moteur afin d'en assurer le refroidissement ?!?!?
Best regards,
Maël.
Cooling maybee ?!?!?
It may be some kind of vent allowing the air to flow out of the engine compartment.
In order to cool the engine, there must be an airflow around it. And in order to have an airflow there must be a way in "front air intake" and a way out "that kind of vent"... maybe.
Cette solution est peut etre déstinée à faciliter la circulation d'air dans le compartiment moteur afin d'en assurer le refroidissement ?!?!?
Best regards,
Maël.
-
Trevor WILCOCK
- Brevet de Base
- Messages : 65
- Enregistré le : 13 mai 2005 16:02