Every year fewer and fewer aircraft with piston engines. Lightweight, economical running on cheaper than gasoline, fuels, jet engines replacing piston even from agricultural aviation. But in any aeromodelling competition still reigns “piston era”. On kartodromo you will see the masterfully made copies of “Ilya Muromets”, “Nieuport”, I-15, Yak-3… do Not attempt to only search for a model jet aircraft — the era of rapid modern machines in modeling has not yet arrived. The reason is the lack of jet motors or at least their imitators: piston motors with impellers. Unfortunately, numerous attempts by modelers to create quasirational the engine was not successful — usually these devices have extremely low efficiency and did not develop the thrust required for steady flight of the model.
A more successful version of the EDF managed to build a veteran Soviet aircraft modeling gorkovchanin p. P. Smirnov. “Desyatkova” two-stage motor fan with own weight 830 g develops a thrust of 2.25 kg/s. And that is enough for a flight not only cord, but radio-controlled models-copies.
In the work to create quasirational engine optimal design proposed to be included and the readers of our magazine, to talk about self-developed structures to share ideas and plans. The best solutions will be published.
The design of impeller before me stood a task — to obtain maximum thrust (and therefore maximum efficiency of the propeller) with a minimum diameter of the fan. This was possible only when the impeller two-stage scheme. The blades of the first and second stages are located in the annular channels between the blades guide vane units.
Initially, the air flow gets to the inlet guide vanes is an annular channel in which are 11 radial profiled blades. Each of them is installed at an angle of 15° to the direction of the air flow that gives you the opportunity to spin it in the direction of rotation of the rotor. This reduces the flow velocity relative to the rotor blades of the first stage impeller.