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Robbiesmurf

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Viewing 15 posts - 181 through 195 (of 473 total)
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  • in reply to: Horespower, thrust, clydesdales and making babies. #858878
    Robbiesmurf
    Participant

    The tractor paraffin, is it coloured red?
    Gas turbines normally had atomisers. An exception I know of was the AS Sapphire series engines which had vapourisers (‘hockey sticks’) and a couple of atomisers for starting. The combustion chamber was annular.

    in reply to: test pilot: "F-35 can't dogfight" #2171869
    Robbiesmurf
    Participant

    In this case, I think the F-35 could pod the wings.. Upon ditching them, the pilot would not recognize much of a difference in the agility, anyway..
    Have a nice day 🙂

    You’re aware of the lifting-body experiments I see….

    in reply to: test pilot: "F-35 can't dogfight" #2171952
    Robbiesmurf
    Participant

    So we have a caveman claiming to be a pilot, who says F-35 cannot do energy maneuverability, and that is based on maneuvers done in high AOA controllability test? Lets just dismiss it as yet another BS from another pilot quote and be done with it. To be honest, I doubt an actual pilot can be so ignorant.

    You do meet so many who claim to be professionals, and yet, they are unable to answer a simple question in their field of expertise…..

    in reply to: test pilot: "F-35 can't dogfight" #2171955
    Robbiesmurf
    Participant

    I am glad thet F-35 is only marginally slower when flying from Ugolny ( Russia ) to Nome ( Alaska ) than a Saab J-35 Draken according to Microsoft FSX. :highly_amused:

    X-15 is 4 times faster than A-10 and F-35. :angel:

    Ta-152C is 15 minutes slower.

    F-104 and F-22 are the fastest jets…not even a Mig-21 can beat them ( though I haven’t tried Mig-31 ).

    Could you please explain these details in percentages, some posters here would find that more credible..

    in reply to: Horespower, thrust, clydesdales and making babies. #859353
    Robbiesmurf
    Participant

    Would that be US gallons or Imperial gallons?

    Is it an African or European Swallow?
    Fortunately, US and imperial pounds are the same.

    in reply to: Horespower, thrust, clydesdales and making babies. #859356
    Robbiesmurf
    Participant

    ISO standards are insidious……

    in reply to: Horespower, thrust, clydesdales and making babies. #859467
    Robbiesmurf
    Participant

    Interesting points about fuel, certainly with turbine engines. The specific mass is indicative of it’s calorific value (heat it produces). AVTUR = 0.78, AVTAG = 0.76, AVCAT 0.80 Diesel = 0.82. Sfc is expressed in lb fuel/lb thrust/hr for piston engines gr/kW/hr. The stoichiometric ratio for fossil fuel engines is about 15:1 (15lbs of air to 1lb of fuel) The gallons tells you how much to pay, the weight tells you how far you can go..
    The problem with shoving AVTUR into an AVGAS engine is the fuel needs to be better atomised (high pressure).

    in reply to: Horespower, thrust, clydesdales and making babies. #859750
    Robbiesmurf
    Participant

    [ATTACH=CONFIG]240923[/ATTACH]

    Take note, British horses are stronger than European…..

    in reply to: Horespower, thrust, clydesdales and making babies. #859782
    Robbiesmurf
    Participant

    This one too?
    [ATTACH=CONFIG]240927[/ATTACH]

    in reply to: Horespower, thrust, clydesdales and making babies. #859859
    Robbiesmurf
    Participant

    Yes, it transmits no power to the aircraft!

    Power = force x distance / time

    (It is a little less clear in imperial that the lbs are used as a unit of force here rather than mass.)

    All the other clever stuff is covered in the thrust rating of the engine at a given aircraft speed.

    Thrust ratings given by manufacturers are given SLS. Static, sea-level.
    When it moves and goes high altitude, things change quite radically.

    in reply to: Horespower, thrust, clydesdales and making babies. #860011
    Robbiesmurf
    Participant

    I don’t see how the aircraft speed comes in to it ?
    It would suggest that if the aircraft were stationary the engine would produce no power.

    Isn’t it more to do with the mass flow ( of air ) through the engine ?

    Thrust = Mass airflow x velocity differential (forward speed of a/c and rearward speed of airflow). For the first couple of hundred knots, thrust actually decreases. At about 300 knots you start to get ‘ram recovery’. As the speed increases, the pressure in the intake increases. The pressure ratio is dependant on the rpm, and the ram pressure.
    By designing the intake correctly you can increase the total pressure ratio dramatically.
    The variable geometry intake on Concorde increased the ambient pressure to 6:1 at Mn2.0. The engine pressure ratio is 10:1 at cruise rpm. Total pressure ratio is then 60:1 (6 x 10). Simply put, you shove a lot more air in the engine (mass) when moving fast. Also, the higher the pressure, the better the thermal efficiency (added heat turned into oomf).
    I have read somewhere that the SR71 was producing a pressure ratio in the intake to 34:1 at operational speed (Mn3.2). The engine had a pressure ratio of some 7.5:1. It was actually a turbo-ram jet. The engine itself was effectively a ‘flow inducer’ at high speed. It was only producing about 15% of the total thrust. The rest was produced by the intake, bypass section and reheat pipe

    in reply to: Horespower, thrust, clydesdales and making babies. #860303
    Robbiesmurf
    Participant

    It has been said that when Whittle had the first running engine, it produced 1,000lbs of thrust. Stanley hooker of RR went to Hives and told him of it. “Can’t pull the skin off a rice pudding” said Hives.
    Hooker went away and did some calculations.He went back to Hives and asked him, “how much thrust does a Merlin produce?” “I don’t know” replied Hives. “1,000lbs” said Hooker. It is said, that is when RR decided to enter the jet-age..

    in reply to: The PAK-FA News, Pics & Debate Thread XXV #2173189
    Robbiesmurf
    Participant

    Guys……..

    I posted the EE P1 photos tongue-in-cheek – I didn’t intend to start a flame war.

    Ken

    Ken

    My thoughts too, that’s why I replied to the Bf 109 pic…
    The Lightning already had a vortex reducing feature on the mainplane. The later versions (F6 & 2a) had kinked & cambered LE’s.
    I’m not after a flame war, I just asked a question.
    Nice pic btw.

    in reply to: The PAK-FA News, Pics & Debate Thread XXV #2173223
    Robbiesmurf
    Participant

    Just looked it up. A LEVCON is a Leading Edge Vortex Control. So what does a slat do?

    in reply to: The PAK-FA News, Pics & Debate Thread XXV #2173282
    Robbiesmurf
    Participant

    True, but they were automatic…..

Viewing 15 posts - 181 through 195 (of 473 total)