# SAIL ON THE AIRWAVES

Modern rules are open to athletes ample opportunities fast and seaworthy yachts class F5Х. The latest trends of the industry that arose in the design of the high speed of these yachts, the latest advances in technology and the use of new materials — all embodied in the design of RC sport model.
When the conditional measurement area 0.75 m2 actual area of the sails in the class F5Х today can exceed 1 m2, when the mast d of 19 mm and a height of 2.5 m sail area reaches 1.4 m2. The use of such materials as Kevlar, carbon fiber, and the transition to vacuum forming technology allow us to create a model of minimal displacement of 8.5 — 9 kg ballast weight 6 kg.

RC model yachts F5Х

These are the main parameters of the most perfect models of yachts. What are the possibilities of further improving the ride quality? To understand this, consider a model that showed the best results in the championship of the USSR in 1985.

The body of the model.

In its design, special attention was paid to the maximum rapidity all-weather “boats” with an achievable speed of 3— 4 m/s in videosmassage mode.

Host grotto swivel-boom with a lanyard.

Calculations show that the Froude number that defines the main hydrodynamic characteristics of the flow around buildings (WG), for the proposed model of the yacht with К8Л = 1.5 m at a speed of 2 m/s 0,52 different. As according to fluid dynamics for p=0.5 of about 60% of the total resistance is of the wave, it becomes clear — the focus should be given to its reduction, and the reduction of resistance forms, not forgetting, however, about the third term the total resistance of the hull is about friction. It can be treated as reducing the amount of wetted surface of the hull and creating a “laminar” waterline fully tightened to the stern.

The node adjustment swivel the jib boom.

Try to estimate the power of this model for weak and strong winds. In this case we will use dimensionless criteria Brussa.

For strong winds:

Snap. — sail area is 1 m2,
D — displacement, taken 0,00885 T.

For weak winds:

Scm. POV. — wetted area of the hull, taken 0,316 m2, for model yachts can be determined by approximate formula Groote:

The values suggest that the model has high power in strong winds with quite satisfactory characteristics in weak winds.

The projection of “housing”

Let us dwell on the structure of the model itself. In the study of the theoretical drawing of the hull once you pay attention to the sharpness of the waterlines in the nose and very flat buttocks aft. This configuration was chosen due to the fact that “boat” is designed for maximum speed.

The housing consists of two layers of Kevlar material with a sizing compound on epoxy K-153. From the nose pillers to the rear edge of the keel inside Vileika strengthened platinu. Method of manufacture forming in the matrix using vacuum technology. A properly made casing after gluing weighs 1250-1300 g. Right and left halves of veclachi connected via DP based on epoxy resin, reinforced seam flanges. These items are highly loaded zone at the same time enhance the rigidity, act as Edelweiss and the keel timber and make a stronger and monolocale best for this model, the rotation axis of the jib-boom is shifted by 45 mm from the tack angle in the stern, which reduces the shading of the headsail the headsail.

Modelbinders with Paterson.

After manufacturing the hull, keel and rudder are carefully painted and polished. The model is equipped with a control equipment “Varioprop”. However, it should be noted that good results can be achieved with other equipment. So, in a similar boat with the “Signal FM-7” securely managed in wind up to 12 m/s.

Accurately and precisely executed model is operated easily and does not require any additional adjustment of pelagonia center sail genuine case. Adjust and configure the RC on the water do not cause problems and are performed in the traditional way. Properly adjusted the boat on the tack “galfvind” and “backstay” neutral tack “the wind” is very poorly reproduced.

Nose pillers.

It should be noted that the model class F5Х with the long waterline and high power imposes certain conditions on the conduct of the race. For the realization of the speed advantages of the sides of the triangle, where the wind is favorable, it is desirable to pass backstage, not gybing. For Lavrovich sides preferred “racing the wind” and not “sharp wind”, without positional tactical combat, although the model can go very cool and capable of such a confrontation. Athletes with racing experience in classes F5М and built the model must learn the peculiarities of driving new technology in calm conditions. The fact that such a yacht has a much greater radius of circulation than the model F5М and longer turns “tack” and “jibe”.

K. GOLOVIN,master of sports of international class,Kazan