KingTech K-45G涡喷发动机评测
作者：COLIN STRAUS图片：COLIN STRAUS
原载《Radio Control Jet International》杂志2015年8-9月刊
The K-45G package is very complete apart from the required 9.9 V LiFe ECU battery pack
Turbine Package Contents:
KingTech K-45G Turbine
Fuel Pump (HP Tech ZP25M)
Xicoy ECU (Electronic Control Unit)
System Analyser
Leads
Instruction Manual
Fuel Tubing
Manual Fuel Valve
Fuel Filter with mounting clips
Decals
For some years many of the new turbines that have been developed have been of between 80 and 220 Newtons thrust, meaning that there are only a handful of smaller turbines currently available,with a rather large gap between the very small Lambert Kolibri and JetCat P20-SX turbines and the venerable JetCat P60-SE, only the long established Wren 44 slotting in the middle of this range.
Well now there is a new contender, the KingTech K-45G from Taiwan, which as its name suggests, is designed to produce 4.5 kg of thrust from its compact dimensions, being only 76 mm in diameter and with an overall length of just 195 mm. Weight of the turbine is just 700 grams, and this includes the fuel and kerostart valves, as these are internally mounted under the front cover. What You’re Getting
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 I quickly unpacked the engine for a close look.
The turbine itself continues the now familiar KingTech styling and colours, with the use of a graduated gold colour for the main case alongside red anodised aluminium parts,whilst the external appearance is reasonably uncluttered, with the kerostart unit being internally installed, however, unlike some other KingTech turbines the thermocouple is external.
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 as previously mentioned, in addition to two electrical connections, the lightweight data cable and heavier starter and kero plug lead.
As is becoming de-rigueur now for higher performance turbines, the K-45G has a machined compressor, this being superbly produced and with a mirror-like finish, the turbine wheel meanwhile being similar (but substantially smaller) to that fitted to previous engines.
Also supplied is the popular and reliable Xicoy ECU together with matching System Analyser/Programmer, HP-Tech ZP25M fuel pump as well as all required leads, tubing,fuel filter and manual fuel valve but no FOD guard, this having to be supplied by the owner if required. No battery is included, the required 3-cell, 9.9 V LiFe pack also having to be supplied by the owner.
The generic, very well written and detailed 53 page English language manual is also included, however this is listed as covering the range of KingTech engines from K-60 to K-210, the brand new K-45G not being specifically mentioned. Having said this,the installation and set-up procedures are exactly the same as for the larger turbines,as are all of the safety precautions, lifetime warranty details etc., so it is only the specific performance and specification information that is missing, this being available on the KingTech website.
Almost identical to the large K-60G, this new and very compact turbine is ideal for smaller and less expensive models
The popular and effective Xicoy ECU is extremely small and light
The beautifully machined compressor is buried well back down the intake
Nice machining work is evident at the rear of the turbine, note the neatly produced turbine wheel and the balancing marks
Testing
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, in this case using my standard fuel mix of Kerosene with 5% Mobil II oil, although of course the engine will also run very happily on Diesel, in common with all other KingTech turbines.
The first start from cold took just over 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 increasing 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. The engine ran very smoothly throughout the rpm range with good stability at the various points in the rpm range used to record data.
Acceleration was good at around 4.5 seconds,with deceleration taking a similar time, these figures being very slightly down on some of the recent KingTech engines I have tested, which had outstanding acceleration/deceleration performance. The corrected full power figure of 4.1 kg thrust was however some little way below the 4.5 kg claimed, although the engine was running at the full rated rpm.
Also well below the suggested level was the full throttle fuel consumption at only 143 grams (178 cc) per minute instead of the 155 grams shown in the K-45G specification.
Concerned about these performance figures, which suggested that the engine was running below its optimum performance I spoke to John Wright, who had also recently bought a K-45G. He then kindly ran his engine on his own test rig, and obtained almost identical figures, which confirmed that there was more performance to be had.
A brief email discussion with the factory ensued, the outcome being that the ECU was unlocked to allow an increase in maximum rpm – the standard limit was 162,000, however the factory advised that the compressor was safe well beyond this level.
In the event I set the new maximum rpm to 170,000, this still being well below the safe rpm limit for the compressor. Running the engine at this new maximum rpm was equally uneventful, but of course the thrust and fuel consumption both increased significantly, with the new maximum power being a corrected 4.6 kg, whilst consuming 160 grams per minute, matching the claimed figures almost exactly. The exhaust gas temperature was still relatively low at a maximum of 674°,suggesting that the engine was still running quite conservatively, with performance in hand.
Supplied with the turbine is this very compact fuel pump, manufactured by HP-Tech
Turbine mounted on the test rig and ready to go for its first test run
Impressive
Having spoken to the factory it appears that the pre-set maximum rpm figure may be amended in the future to enable all users to obtain the full 4.5 kg thrust that the engine is clearly capable of, and at this level and with an exceptionally competitive price the K-45G is going to be very popular, being ideal in converting some of the older ducted fan airframes, as well as for more modern designs and for fitment to mid sized gliders to provide the require get up and go!
The K-45G is yet another very impressive KingTech turbine, which will run very well on a variety of fuels, starts without drama or fuss, is powerful for its compact size, has good throttle response and a confidence inspiring warranty.
www.kingtechturbines.com 都是英文，不明白:lol 好袖珍，比我们的小多了
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