JH-7/JH-7A/JH-7B Thread

[challenge]

Re: JH-7/JH-7A Thread

JH-7A biggest problem may be her engine,during her flight demonstration in 1998 Zhuhai airshow,a lot of western magazine reporter who witness the flight
claim that the aircraft suffer from underpower.
Spey engine was technically a early 60's engine,T:W ration at 6.2 below that of RB-199 which as T/W ratio of 7.5.but improve engine call WS-15 will replace the WS-9.
according to technical data posted in WMF,her max.thrust and dry thrust has not change except her weight which increase her T:W ratio to 6.9
in the future,we may be looking at improve WS-15A/B/C model.

 

[SteelBird]

Re: JH-7/JH-7A Thread

sorry，no link for this accident，I read it in dingsheng forum by chance，but the thread was deleted shortly.

If there is no link, the accident might be fake. I searched the internet and found nothing. In case such a serious accident happens, you'd see speculation spreading through the web very quickly.

 

[Blitzo]

Re: JH-7/JH-7A Thread

JH-7A biggest problem may be her engine,during her flight demonstration in 1998 Zhuhai airshow,a lot of western magazine reporter who witness the flight
claim that the aircraft suffer from underpower.
Spey engine was technically a early 60's engine,T:W ration at 6.2 below that of RB-199 which as T/W ratio of 7.5.but improve engine call WS-15 will replace the WS-9.
according to technical data posted in WMF,her max.thrust and dry thrust has not change except her weight which increase her T:W ratio to 6.9
in the future,we may be looking at improve WS-15A/B/C model.

Isn't the WS-15 a heavy thrust engine for the 5th gen plane/J-XX under development? Would they use such an engine on the JH-7A..?
Or is it a whole different designation all together?

 

[Lion]

Re: JH-7/JH-7A Thread

JH-7A biggest problem may be her engine,during her flight demonstration in 1998 Zhuhai airshow,a lot of western magazine reporter who witness the flight
claim that the aircraft suffer from underpower.
Spey engine was technically a early 60's engine,T:W ration at 6.2 below that of RB-199 which as T/W ratio of 7.5.but improve engine call WS-15 will replace the WS-9.
according to technical data posted in WMF,her max.thrust and dry thrust has not change except her weight which increase her T:W ratio to 6.9
in the future,we may be looking at improve WS-15A/B/C model.

2002 JH-7A was introduced and reported using WS-9II which is up thrust. The fact PLAAF also induced it say about something the improvement over JH-7 in 1998.

 

[challenge]

Re: JH-7/JH-7A Thread

2002 JH-7A was introduced and reported using WS-9II which is up thrust. The fact PLAAF also induced it say about something the improvement over JH-7 in 1998.

there's no WS-9-2. WS-9 is copy of spey engine.
But what JH-7A really needed a high T:W ratio engine such as F-414 or EJ-2000 engine.although during the 2008 airshow, Liming displayed a mock up of new 90kn TF engine.but the IDR reported that the russian is developing a follow on to RD-33/93 engine with 100~105 kn thrust to power MIG-35.

 

[Lion]

Re: JH-7/JH-7A Thread

there's no WS-9-2. WS-9 is copy of spey engine.
But what JH-7A really needed a high T:W ratio engine such as F-414 or EJ-2000 engine.although during the 2008 airshow, Liming displayed a mock up of new 90kn TF engine.but the IDR reported that the russian is developing a follow on to RD-33/93 engine with 100~105 kn thrust to power MIG-35.

There is no WS-9II but a Qingling II which is an improvement of WS-9

Designer of JH-7, Chen Yijian

July 21 (Chinese Military news cited from globaltimes and written by Liu Chang) –Reports on China’s intention to cooperate with aircraft engine makers in the UK and France to improve the performance of the turbofan of PLA fighter bomber JH-7, are denied by the chief designer of the aircraft, Chen Yijian, Academician of Chinese Academy of Engineering. According to Chen, China has also already fixed problems with the JH-7 turbofan, Hong Kong newspaper Ta Kung Pao reported.



Also known as the Flying Leopard, JH-7 initially used the WS-9 Qinling turbofan, which were from turbofans produced by the Rolls-Royce Spey company in the UK. But after years of research, China has fixed problems with the turbofans of Flying Leopard on its own, according to Chen.



Chen went on to say that China’s research on turbofans is still lagging behind compared with some other countries, especially the turbofans of large aircrafts. China has been calling for more research talents to help solve this problem. He said the third generation of China’s fighter bombers, including the J-8 series, J-10 series and the Flying Leopard, have taken shape of a combatant power, and will appear in the Military Parade to celebrate the 60th anniversary of the nation.



According to Ta Kung Pao, China began research on the WS-15 Qinling-2 Turbofan in 1998. The Qinling-2 Turbofan is an improvement on the WS-9 turbofan, with increased pre-heating temperatures on the turbines and reduced weight for greater efficiency. Tests on the Qinling-2 Turbofan in October 2008 were successful. It is now technically competitive to the late M53-P2 engine from France.

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[Roger604]

Re: JH-7/JH-7A Thread

No clear answer was ever given for these photos. Is this a coincidence only, or does China have a JH-series strike fighter program?

It does make a lot of sense to have a F-35 inspired strike fighter to complement air superiority fighters J-14 and J-10B (hi-lo).

 

[AssassinsMace]

Re: JH-7/JH-7A Thread

Richard Fisher has written that China has an F-35-like program underway. He's the only person I have personally read say such a thing given that his articles are basically cut and paste from Chinese forums like this one. I don't know where he got that idea unless he's making those conclusions based on the above coockpit instruments panels. The only other source may have come from reports earlier of China buying a license for the Russian VSTOL but then that ain't no F-35.

 

[challenge]

Re: JH-7/JH-7A Thread

大喜!双发双座全天候隐身歼轰机jh-7b在西飞试飞成功(
________________________________________


日前 据西飞相关可靠人士透露： 新型隐身飞豹jh-7b已经试飞成功!并已经定型，新歼轰－7b是一种双发双座双垂尾翼气动布局的全天候隐身歼击轰炸机。虽然有原飞豹的"身骨"垫底，但是为了适应新型的大推力发动机，因此不得不将新飞豹机身尺寸进行适度放大调整。由于新型发动机的进气量和单位推力比原发动机增强了近50%以上，加之隐身外形的设计需要，所以新飞豹无法简单的沿用和放大原飞豹的机体。新型“贝斯”发动机比“涡扇ws－9"和"劳思赖斯"发动机直径要大，而且也短。因此，有关科研人员对原机的气动外形以及内部机体结构进行了大刀阔斧的改进!其工作量之大之复杂，绝不亚于从新设计一架新飞机。

飞豹jh-7a与jh-7b侧视比例图
在经过了科研人员的辛勤努力，"飞豹－7b有了"脱胎换骨"的表现。歼轰－7b采用当代最前沿dsi蚌式i进气道设计，机身大量采用新型符合材料，因此飞机机体重量比以前轻了许多，而且机体结构强度也比原来有所增强。 由于机体增大使机内燃油量大幅增加，因此歼轰－7b的作战半径在我军现役装备的几种新型作战飞机作战半径中首屈一指。

外形看；中国的“歼轰－7b”改用了新设计的中等后掠角带前缘襟翼式上单翼。另外，为了提高隐身性能和强化气动外形，“jh-7b”使用了“s”形进气道，并在进气道内喷涂新型纳米吸波涂料，以减少飞机正面雷达反射截面积和红外线信号特征，并且具备翼身融合技术，全机新型复合材料的应用明显增加。“歼轰 -7b”的加油方式已经改改进为内藏伸缩“软式”加油设备，以此来进一步加强整机的隐身性。因此，“歼轰－7b”是中国首种使用电脑辅助设计修正外形的隐身歼击轰炸机。

从隐身性能看;由于“歼轰－7b”使用了新研制的隐身吸波涂料，使得该机被探测到的概率大为降低。此外，后期改良型号将加大新型复合材料的使用面积，座舱盖边缘，武器内置且武器舱门边缘等处采用锯齿状的结合线条，可以有效的降低雷达波的反射。由于机载武器采用了内载式和外挂兼顾的方式，以此来进一步降低红外特征。预计由于采取了有效的隐身措施后，“歼轰－7b”的雷达横截面（rcs）将不大于xxx平方米。


这是歼轰－7a的后驾驶舱屏显.歼轰－7b不应低于这个水平。

 

[danielchin]

Re: JH-7/JH-7A Thread

I think I found the link:

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Most comments posted after thought it's highly unreliable, but interesting though....