KingTech K-210G涡喷发动机评测
作者：COLIN STRAUS图片：COLIN STRAUS
原载《Radio Control Jet International》杂志2014年10-11月刊
The Kingtech K-210G package is very comprehensive, and even included a FOD guard
Turbine Package Contents：
Kingtech K-210G Turbine
Fuel Pump
Xicoy ECU (Electronic Control Unit)
System Analyser
FOD (Foreign Object Damage) Guard
Leads
Instruction Manual
Fuel Tubing
Manual Fuel Valve
Fuel Filter
Decals
Right from early on in the availability of commercially produced model gas turbine engines by far the most popular size has been based on the original KJ66 design, with engines having a diameter of around 112 mm. The first engines of this type that became available gave maximum thrust figures of around 80 Newtons,then over time we saw a steady increase through 120, 140, 160 and finally 180 Newtons without any significant change in the size or weight of these much more powerful engines.
Recently there has been another step up in power, with engines that are claimed to give 200 to 220 Newtons being offered for sale. Until now RCJI has been unsuccessful in obtaining one of these engines for test, however this has now changed with Kingtech of Taiwan being happy to provide an example of their new K-210G turbine for test, and as can be seen from the test results, their confidence in this new engine was not misplaced. In the Box
Supplied in the usual heavy-duty cardboard box, and well protected with a shaped foam inner, the turbine and ancillary parts arrived safely after their long trip from Taiwan, and no time was wasted in unpacking the engine and taking a closer look. The turbine itself continues the now familiar Kingtech styling and colours, with the use of a graduated gold colour for the main case and red anodised aluminium parts, whilst the external appearance is very uncluttered, as the kerostart unit and thermocouple are internally installed.
Connections to the turbine total three, a single fuel input, as the kero and fuel valves are mounted under the front cover of the engine, in addition to two electrical connections, the lightweight data cable and heavier starter and kero plug lead. New for the K-210G is a machined compressor, this being superbly finished and with a mirror-like finish, the turbine wheel meanwhile being similar to that fitted to previous engines.
Also supplied is the popular and reliable Xicoy ECU together with matching System Analyser/Programmer, HP-Tech fuel pump as well as all required leads, tubing, fuel filter, manual fuel valve and FOD guard. The very well written and detailed 53-page English language manual is also included, this covering the entire range of Kingtech turbines, and including all of the ECU parameters for each engine.
It also covers the details applicable to the very comprehensive lifetime warranty Kingtech give, which is even transferable to a second owner in the event the turbine is sold on, although of course there are some specified requirements in this event.
The K-210G has very compact dimensions for such a powerful engine, note also the Ali Machinchy signature engraved into the front cover
Very nice machining is evident in this view of the compressor, as well as the minimal blade tip clearance
Extremely crisp casting work can be seen in the turbine wheel, with an interesting colour graduation along each blade
This very neat, rotatable fuel connector allows the fuel line to be run as required by any installation On Test
The engine was soon installed onto the test rig and had the fuel and electrical cables hooked up, the ECU and fuel pump plus filter connected and battery plugged in, a 3-cell, 9.9 V 2100 mAh pack being used for all the test runs. Programming the ECU to the radio being used is very simple, as is priming the fuel line up to the engine, the tubing being disconnected from the turbine whilst this was being done to eliminate any possibility of flooding the turbine with fuel. Once this was completed the start settings were adjusted to those shown in the manual for Kerosene fuels,these being slightly different to those used when running on Diesel.
The first start from cold took around 1 minute, and this was typical for further cold starts, the time for starts from warm being slightly shorter. Nothing untoward was evident, the engine just going through the various stages smoothly until the start sequence was complete and the ECU passed control over to the radio.
The engine was allowed to idle for a period to enable the ECU to more accurately stabilise the exact idle rpm, then the throttle was opened gradually to full, and the engine accelerated up to just below full rpm, the ECU then steadily increased the power until full power was reached, this process setting the full power rpm and overall throttle range.
With the power reduced to idle the test process was started, with the engine being run at a range of power settings, where thrust,EGT and full consumption were measured. All of this was completed without any fuss, the engine performing very well throughout, even at the top of the power range. I did notice a slight instability of rpm at times, with the rpm varying by a few hundred up or down, but in operation this would not be noticeable, and as the fuel pump runs in this minor instability should disappear.
The corrected full power figure of 21.1 kg thrust is fractionally above the claimed figure of 21.0 kg, as is the recorded full power rpm of 121,500, the manual suggesting 120,000. Fuel consumption was also slightly above that claimed, with the recorded figure being 631 grams (789 ml) per minute at full power, rather than the manual’s figure of 590 grams (738 ml) per minute. For a powerful engine such as this the idle thrust was particularly low, at only 6.2 Newtons (0.6 kg), which is a great help on an approach into a small strip.
Notably, the K-210G has the best power to weight ratio of any turbine we have yet tested,based on maximum thrust compared to the overall weight of the engine including ancillaries and fuel for 5 minutes at full power, although this record has always been held by one of the more powerful engines, as they tend to be more fuel efficient and the ancillaries weight is proportionally lower.
As I have come to expect from Kingtech turbines the acceleration and deceleration figures are excellent at around 3.5 seconds from idle to full power, and 4 seconds for full power down to idle.
After a very straightforward and fuss-free test programme had been completed the supplied FOD guard was installed to see how this would affect the thrust of the engine, and another run showed that only around 1 Newton was lost with the FOD guard fitted, a very small price to pay for the protection to a valuable turbine a FOD guard provides.
Ready for its first test run, the K-210G looks attractive in its graduated gold and red finish Diesel too!
Once the testing on Kerosene had been completed the fuel system was drained and refilled with Diesel fuel, mixed with 4% Mobil II turbine oil (in the middle of the 3 to 5% oil recommended by Kingtech for the K-210G). A full repeat of the test programme was then carried out running on this Diesel mix, and it was found that the corrected full power thrust figure was identical to that recorded when running on Kerosene, although as the maximum rpm remained the same, governed by the ECU, it was to be expected that the power level would not vary.
What was more surprising was that the fuel consumption was almost exactly the same as when running on Kerosene, as the higher calorific value of Diesel should mean that less fuel would have to be consumed to provide the same amount of power.
Similar testing that has been completed at the factory found that running the engine on Diesel gave a small increase in power over Kerosene, allied to a reduction in fuel consumption of up to 10%, so it is possible that the exact composition of Kerosene and/or Diesel varies from country to country, and that other users may notice the same outcomes as that of the factory when running on Diesel.
All other characteristics seemed to remain the same, with acceleration/deceleration being identical, as was the general running behaviour, the only difference that was noted was that smoke was now being produced by the engine during both the start and shut down sequences, this being relatively light in nature whilst the engine was starting, but quite significant during shut-down.
The supplied FOD guard was fitted for one of the test runs; its use resulted in almost no loss of thrust
This neat System Analyser is included in the K-210G package, here showing the engine running at the recorded full power rpm of 121,500
The polished tailcone soon changes due to the very high temperatures through this part of the engine,with this appealing variation of colours
Conclusions
Once again I have been very impressed with a Kingtech turbine, the K-210G runs very well on a variety of fuels, starts without drama or fuss, is very powerful, has great throttle response and a confidence inspiring warranty.It even comes complete with renowned jet pilot Ali Machinchy’s signature!
Contacts：
www.kingtechturbines.com
页:
[1]