Chinese Engine Development

I agree with both Chuck and Xiabonan. However, I have read several well written posts indicating the technological gap in the engine field is widening between Chinese and Western counterparts.

I'm sure most of us have taken Econ 101 as an elective in university. The quick advancement in Chinese engine industry is simply a classic catching-up effect phenomenon taught in macro-economics. Because of the widely available foundational research contributed by the Western academics in the past few decades, the Chinese engineers can advance much quicker than their American predecessors in tackling similar old problems. But the classic Moore's Law indicate the pace of forefront innovation and advancement itself is also accelerating. Hence while the Chinese are quickly catching up with quick trots, Uncle Sam can easily maintain its lead by big slow strides.

So the Chinese might be always able to catch up quickly, but there will always be a little gap between the two, like the enduring minute advantages of US to Soviet engines during the Cold War.

It's easy to talk about advances in China engine developments, but if it's going so well, then why don't we see widespread use of WS-10s in J-10B and J-15 production models, and WS-13s in JF-17 Thunders? Continued importation of Russian engines paints a different story than the supposed 'successes' in Chinese engine design and production.

Verum said:

I agree with both Chuck and Xiabonan. However, I have read several well written posts indicating the technological gap in the engine field is widening between Chinese and Western counterparts.

I'm sure most of us have taken Econ 101 as an elective in university. The quick advancement in Chinese engine industry is simply a classic catching-up effect phenomenon taught in macro-economics. Because of the widely available foundational research contributed by the Western academics in the past few decades, the Chinese engineers can advance much quicker than their American predecessors in tackling similar old problems. But the classic Moore's Law indicate the pace of forefront innovation and advancement itself is also accelerating. Hence while the Chinese are quickly catching up with quick trots, Uncle Sam can easily maintain its lead by big slow strides.

So the Chinese might be always able to catch up quickly, but there will always be a little gap between the two, like the enduring minute advantages of US to Soviet engines during the Cold War.

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Just a note. Moore's law applies only to computing power, not all technology and innovation.

Let's also not risk presuming that it is impossible for one country to catch up and then surpass another technologically. Specific factors dictate pace of technological innovation, not broad trendlines.

Verum said:

But the classic Moore's Law indicate the pace of forefront innovation and advancement itself is also accelerating. Hence while the Chinese are quickly catching up with quick trots, Uncle Sam can easily maintain its lead by big slow strides..

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Uncle Sam only seem to maintain its lead (in engine performance) because its lead was so large to start with and near the beginning it is easier to overlook the closing distance from ahead than from behind.

Outside computation speed and microchip density, I doubt you would find many instances of compliance with Moore's law in rates of technological progress as measured in performance metrics. In fact, with most things, the rate of technological progress as measured by performance metrics exhibit the the reverse of the Moore's law, the more advance the basic technology, the less increase in performance is there to be obtained via same amount of additional time and effort invested in research.

I think if both China and America maintain comparable levels of reserach investment in jet engine technologies, the nominal lead in Uncle Sam's technology in terms of years of research effort will remain, but the actual implication of this lead as expressed in superior performance of the will diminish. Performance of Chinese engines as plotted against time will asymptotically approach that of American engines even as American retains a constant lead in the total amount of research.

Blackstone said:

It's easy to talk about advances in China engine developments, but if it's going so well, then why don't we see widespread use of WS-10s in J-10B and J-15 production models, and WS-13s in JF-17 Thunders? Continued importation of Russian engines paints a different story than the supposed 'successes' in Chinese engine design and production.

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That's very true. Designing a product is very easy, maybe only consists of only 10%-30% of R&D. But refining it and making it perfect is 10 times harder and takes 10 times longer. It takes a long time for the engines to mature. Each generation of US/NATO engines are used for about 20 years before they fully mature.
Unfortunately, China doesn't have that luxury. They have to advance quickly to not fall behind, but this gives the engines little time to be tested and improved. But when it's not tested and improved, they then will lack knowhow in improving on the engines. It's a terribly vicious cycle.

Verum said:

That's very true. Designing a product is very easy, maybe only consists of only 10%-30% of R&D. But refining it and making it perfect is 10 times harder and takes 10 times longer. It takes a long time for the engines to mature. Each generation of US/NATO engines are used for about 20 years before they fully mature.
Unfortunately, China doesn't have that luxury. They have to advance quickly to not fall behind, but this gives the engines little time to be tested and improved. But when it's not tested and improved, they then will lack knowhow in improving on the engines. It's a terribly vicious cycle.

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Something called parallel development. There's less need to
perfect one iteration of a design when you have an accelerated product pipeline and are ready to iterate on the next design. Incentive to prefect one iteration increases as a technological gap decreases and as you approach the current limits of a technology.

I don't agree with the idea that Moore's Law doesn't apply in jet engine field. It's true that the advancement rate diminishes as research of an individual field reaches a certain point, but engine technology is the combination of millions of little factors. Relative to rotary engines, jet engine is still in its relative infancy. We are far from knowing everything about it. Even a slight improvement in single crystal formation or nozzle design could each improve the power/efficiency by few percent. If you just add up just all the minor improvements, it could make enough performance difference of an engine generation. In this day and age, with more and more money pouring into research, the rate of advancement will only accelerate.

The rate of improvement might not exactly double every year, it could be a little more or less. But the concept still applies. The rate will only go up, not down.

Verum said:

I don't agree with the idea that Moore's Law doesn't apply in jet engine field. It's true that the advancement rate diminishes as research of an individual field reaches a certain point, but engine technology is the combination of millions of little factors. Relative to rotary engines, jet engine is still in its relative infancy. We are far from knowing everything about it. Even a slight improvement in single crystal formation or nozzle design could each improve the power/efficiency by few percent. If you just add up just all the minor improvements, it could make enough performance difference of an engine generation. In this day and age, with more and more money pouring into research, the rate of advancement will only accelerate.

The rate of improvement might not exactly double every year, it could be a little more or less. But the concept still applies. The rate will only go up, not down.

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This isn't about opinion. The fact is Moore's law specifically refers only to computing power.

Verum said:

I don't agree with the idea that Moore's Law doesn't apply in jet engine field. It's true that the advancement rate diminishes as research of an individual field reaches a certain point, but engine technology is the combination of millions of little factors. Relative to rotary engines, jet engine is still in its relative infancy. We are far from knowing everything about it. Even a slight improvement in single crystal formation or nozzle design could each improve the power/efficiency by few percent. If you just add up just all the minor improvements, it could make enough performance difference of an engine generation. In this day and age, with more and more money pouring into research, the rate of advancement will only accelerate.

The rate of improvement might not exactly double every year, it could be a little more or less. But the concept still applies. The rate will only go up, not down.

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I actually majored in Electrical and Computer Engineering. Are you trying to imply that we are seeing exponential increases in aircraft engine performance every two years, or, given more lenience, every decade or two? The fact that microchip performance increased so rapidly in the past two decades is the result of rapid advances in lithography, computer aided circuit design, and materials (replacing aluminium conduits). Did we see comparable advances in engine technology in the past two decades? Is the design of next generation engine so revolutionary that it could bestow bomber-size aircraft with fighter level thrust-to-weight ratios? If not, Moore's Law does not apply to aircraft engine development.

The basic metric is the ratio between the maximum and minimum temperature which leads to the Carnot efficiency. The minimum temperature is represented by the local air temperature, the maximum temperature is the Turbine Entry Temperature. We do not see any growth of TET resembling Moore's Law. To the contrary that temperature has been creeping up now for a long time thanks to massive investments in turbine blade production technology.