Choosing the right propulsion system for a boat is often a challenge, especially when standard outboard motors can't do the job. If you're in overgrown water, swamps, shallow water, or having to move on ice and snow, then you're in a situation where you're in trouble. jet-engine It's the only smart solution. Unlike traditional propellers, an air propeller doesn't require immersion, which changes navigation.
The principle of this unit is based on throwing a large volume of air back, creating a jet thrust that pushes the vessel forward. boats or air-glissersThey are not afraid of bottom debris, algae and even complete lack of water, which makes them indispensable for rescuers, hunters and fishermen in hard-to-reach regions.
However, despite the obvious advantages, this system has its own features of operation, which must be considered before buying or self-assembling. Noise The work and specific handling require habituation and safety precautions, and in this article we will discuss in detail all aspects of the selection, design and use of air propulsion.
Principle of work and design features
The basis of any aeroboat is a power plant consisting of an internal combustion engine and an air propeller enclosed in a protective ring. Air propeller It creates airflow that, by acting on the vertical steering wheel or changing the thrust vector, allows you to control the direction of travel, and the absence of submersible parts makes the structure less susceptible to mechanical damage from contact with solid objects.
The key element here is ringThe propeller's speed is usually lower than that of aircraft, which allows for cheaper car or specialized outboard motors, and the efficiency of such a system on water is lower than that of a propeller, but this is compensated by the versatility of the passability.
⚠️ Warning: A rotating propeller creates an invisible and deadly zone around the stern of the boat, and it is strictly forbidden to approach a working aero engine from behind, even if it seems that the speed is low.
The thrust vector is controlled either by turning the thrust valves (deflectors) or by turning the entire propulsion system. The first option is more common on amateur boats, because it is easier to implement; the second option is found on professional rescue boats, where high maneuverability is required.
Why are aero engines so noisy?
The main source of noise is not only the engine, but also the tips of the propeller blades, which can reach supersonic speeds, creating a characteristic whistle. To reduce noise, screws with a large number of blades and a special profile are used, but they are never completely silent.
Advantages and Disadvantages of Air Traction
When deciding on the purchase or assembly of an aeroboat, you need to clearly weigh all the pros and cons. passabilityWhere a conventional motor would instantly wind the grass over lower unit and overheat, the aero engine would continue to push the boat confidently, making them ideal for delta rivers, overgrown lakes and winter fishing.
However, there are also significant disadvantages that cannot be ignored. Fuel consumption These systems tend to be higher at the same payload than propellers, and the efficiency of the operation is highly dependent on the weight of the boat and the condition of the water surface - handling can deteriorate at high wavelengths.
- 🌿 Absolute permeability: the ability to move through shallow water, mud, ice and snow without the risk of damaging the screw.
- 🔇 High noise level: The operation of the engine and propeller creates significant acoustic discomfort, which can scare fish or animals.
- ⛈️ Independence from the environment: No need for water to cool the engine (air cooling is used) and the rotor.
- 🛠️ Ease of maintenance: The lack of lower unit, gearbox and submersible elements makes repair and storage easier.
It is important to note that boats They're not very well controlled in strong side winds because of the large sail structure, which requires the steering wheel to keep constantly monitoring and adjusting course, and it's not necessary to stay calm, but in stormy weather, it becomes a challenge even for an experienced operator.
Engine choice: Gasoline or Electricity?
The heart of any aeroboat is an engine, traditionally used gasoline units, often redesigned car engines or specialized aircraft engines. electric-air-motorThe choice depends on your priorities: power and range or environmental and silence.
Gasoline engines provide high specific power and allow for significant speeds; they are indispensable for long distances and heavy boats; however, they require regular maintenance, fueling and exhaust emissions, which can be frustrating for passengers sitting in the stern.
Electrical options such as Torqeedo base-line brushlessThey're less fuel-smelling and quieter, and their main drawback is their limited battery life, which depends on battery capacity, and for a few hours of fishing in a quiet backwater, an electric aero engine would be the perfect choice.
When choosing a gasoline engine for an aeroboat, give preference to models with forced air cooling. Liquid-cooled engines will require a radiator installation, which will complicate the design and increase weight.
The cost of running the electric option is much lower if you have the ability to charge batteries from the grid or solar panels, while gasoline requires constant financial investment and proper fuel storage, especially in winter.
Types of propellers and their specifications
The propeller is the element that directly converts the engine power into thrust. Efficiency The propellers are two-blade, three-blade and multi-blade, and for aeroboats, the most common propellers are large diameter and small pitch propellers to provide thrust at low speeds.
Wooden screws are cheaper and easier to repair in the field, but they are afraid of moisture and can change geometry. Composite and aluminum screws are longer-lasting, but when hit by a hard object can split or deform without the possibility of repair.
| Type of screw | Materials | Advantages | Deficiencies |
|---|---|---|---|
| Two-bladed | Tree/Composite | High efficiency at low speeds | High vibration level |
| Three-bladed | aluminum | Smoothness of work, balancing | Harder to manufacture. |
| Multi-bladed | carbon | Reduced noise, high traction | High cost |
| Composite | Plastic. | Cheap, affordable | Low resource, sailing |
The diameter of the propeller is limited by the size of the protective ring and the height of the installation above the deck, the optimal gap between the blades and the ring is several centimeters, increasing the diameter of the propeller increases traction, but requires a more powerful engine for promotion.
⚠️ Warning: Never use propellers designed for aircraft on aeroboats without recalculating the pitch. Aviation propellers are designed for high speed forward movement and on site or at low speed boats will operate inefficiently, overloading the engine.
Installation and installation of the power plant
Mounting an aero engine on a boat requires careful preparation and safety, and the design must be rigidly fixed, because vibrations from the engine can quickly shake poor-quality mounts. frame-framewhich is attached to the sides or transom of the boat.
The center of gravity of the installation should be as low as possible so as not to overturn the boat. The engine and propeller are often placed on an elevation, but this increases the sailing speed. It is important to ensure free access of air to the engine for cooling and to the propeller to create thrust.
☑️ Check before the first launch
When assembling a homemade plant, pay special attention to the shaft. It must be perfectly balanced, otherwise the vibrations will destroy the bearings and mounts in a matter of hours of operation. Using a flexible coupling between the engine and the screw shaft helps to extinguish the torsion vibrations.
To control gas and ignition, put the cables or electric drives on a ramper or control panel in the cockpit. The steering wheel must be able to quickly release gas in case of danger. The steering wheel must have minimal backlashes.
Operational rules and safety measures
Operating an aeroboat requires that you follow specific rules other than operating a conventional boat. hearing protectionThe noise level in the area of operation of the aeromotor can exceed 100 dB, which requires the mandatory use of headphones or earplugs for all on board.
The second important aspect is caution when maneuvering near people and animals, exhaust fumes and airflow can be dangerous, and it is also forbidden to move on the boat on the go, since a sharp shift in the center of gravity can lead to tipping, especially on glides.
During winter, the blades must be monitored for icing, the propeller is disturbed by the icing, and can break the propeller at high speeds. Before each release to the water (or ice), conduct a visual inspection of the screw and attachments.
The basic safety principle on an aeroboat is, "The screw is always dangerous." Even after the engine is turned off, the propeller can continue to rotate inertia or be started accidentally. Always keep your distance.
FAQ: Frequently asked questions
Can I put an aero engine on a conventional PVC inflatable boat?
Technically, it's possible, but it requires a reinforcement of the transom and bottom. Conventional PVC boats are not designed to handle the vibrations and weight of a full-fledged propulsion system with a protective ring. There are special models of inflatable aeroboats with a rigid bottom that are designed for this.
What is the maximum speed of the aircraft?
Speed depends on engine power and hull contours. Amateur models develop speeds from 30 to 60 km / h. Sports and racing aeroglissers can reach speeds of more than 100 km / h, but for fishing such speeds are rarely required and dangerous.
Do I need to register an aircraft in GIMS?
Yes, if the weight of the curb vessel exceeds 200 kg or the engine power is more than 8 kW (about 10.8 hp). As aeromotors are often powerful, registration and ownership of a small craft will most likely be required.
Why is the boat difficult to stop?
Aeroboats don't have a reverse in the classical sense (although there are models with reverse propellers), they use the hull's sailing and water resistance to brake, and they take longer and longer to stop than propeller boats, which is something to consider when maneuvering.