J-10 Thread III (Closed to posting)
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MiG-29
Banned Idiot
Let me explain you.
Any Engine has pressure recovery loss tolerance, however if you want less breakdowns, malfunctions and lower and cheaper maintainace then you need the highest pressure recovery percentage, why? can the J-10B fly at mach 2? probably yes, the F-16 did it with DSI, but the problem arises at maintainace and reliability, thus F-35 is kept at its more effective and reliable Mach number 1.6, can it fly faster? yes as long as the airframe and engine combination allows it (in few words if at 87% or lower thrust the aircraft can achieve Mach 2), but the engine will suffer from engine stalls to engine surges, thus due to lower thrust and lower relaibility, engines are provided with variable geometry intakes.
87% is a low number at Mach 2, it means you are not only lowering the thrust of the engine but also lowering the safety margin to operate it.
In a fighter that rarely will venture into Mach 2 or Mach 2.2 well it is okay to have DSIs.
To operate the J-10B at a safety margin under operational conditions then you need 95% pressure recovery.
As such saying the original J-10 has a F-4D type of intake is to say the Chinese designed a less effective fighter than the MiG-29 or Mirage 2000, thus it is even illogic to say the 3 shock intake of the J-10 has equal performance to a 1950s jet is just an insult to Chinese designers.
The original J-10A must have a really good pressure recovery in order to make it fly with a variable geometry intake otherwise a Lavi or F-16 intake is better.
You can continue thinking the DSI will allow Mach 2 without affecting the engine effective service life and maintainability, it is more realistic to say if the J-10B ever goes Mach 2 will be very rarely, a more practical Mach 1.8 is a realistic number, fighters like Rafale or F-18 do it for such a reason.
1) I wasn't talking about the J-10B's top speed. I was pointing out that a DSI's effectiveness is not fixed but dependent on the shaping of the bump and the inlet, and that it is not the final say on pressure recovery because other features matter too, like the tunnel shape.
2) Do you not know how to read...
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MiG-29
Banned Idiot
The DSI has increases effectiveness over other type of fixed intakes at transonic to low supersonic speeds, it is not the most effective intake type, it is simply a intake types that lowers weight, costs and increases stealth at lower prices.
My whole point is J-10B is more effective in terms of transonic speeds if ever, and cheaper costs for stealth, maintainance, and production.
Can you get better performance with other types of intakes? yes the F-14 is a type that will enjoy superiority at Mach 2 over a DSI, same is the MiG-29 or F-15 intake, but these intakes will requiere higher costs for production and maintainance and perhaps higher cost in stealth and lower effectiveness.
The J-10A was designed with a variable geometry for a reason, only when stealth became a more important parameter, then as in the case of F-18E the intake was redesigned.
What part of different bump and inlet geometries and different effects do you not understand.
Here, this article can help you. This is the HTML version
This is the PDF version, it has pictures but you have to download it.
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MiG-29
Banned Idiot
I know the article in fact
It can be seen in figure 49-52 that the bumps are redirecting more of the airflow around theintake in the lower part than in the upper part. On the upper part, the airflow is also redirectedbut since the cowl is swept forward, the airflow is still entering the intake. Since the geometryof the intake was chosen not to be changed, the position of the bump should be changed insteadso that the airflow on the upper part also can be redirected outside of the intake. It is realizedthat if the bump is only repositioned further out from the intake, the airflow on the lower sidemight still be sucked into the intake. A possible solution would be to reshape the bump so that ithas amplitude before the cowls both on the upper and lower side of the intake, i.e. to make itmore square shape. This was the attempt for Intake & Mod
From X-35 to F-35 the intake recieved a change to allow for better AoA handling thus the bump position was changed as the intake cowl was.
The Chinese applied the same change to the J-20 from the JF-17
But still it does not mean it is a four shock intake.
Diverterless Intake
The unassuming bump at the opening of the F-35 inlet works with the forward-swept inlet cowl to redirect unwanted boundary layer airflow away from the inlet. The diverterless inlet, as it is called, is a technology advancement introduced on the JSF. It meets aerodynamic and observables requirements in a less complex manner than previous designs.The geometry of the cowl itself changed from X-35 to F-35. The new geometry provides better airflow into the engine at higher angles of attack. The inlet itself was moved back several inches to reduce weight and cost. White paint on the internal surfaces is unique to the first aircraft. Internal surfaces of subsequent inlets will be painted gray.
red colours are reserved for moderators, please refrain from using it in your posts.
-TUP
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1) I did not say it was a four shock intake.
2) Not all four shocks need to be generated by the bump
3) You don't always need four shocks to get a good pressure recovery at high mach. It's dependent on the discrete geometry of the inlet, the tunnel, and as ie mentioned, even structures in front of the inlet.
Here comes the cavalry, people far more qualified than me
oh no you have to carry the fight on yourself.
you are doing fine.
don't try to argue with Mig-29. he is hopeless.
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