JP2017149189A - Dynamic pressure difference propelled vessel - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve propulsion efficiency by reducing friction resistance, wave resistance, viscous resistance, etc., during advancing of a vessel.SOLUTION: A flow velocity is increased on a front surface part, air compressed on a side surface or a rear surface side is jetted out as fine bubbles to below a water surface, and thus static pressure that becomes a stumbling block in an advancing direction is reduced by increasing dynamic pressure on the front surface part. On the side surface, friction resistance is reduced, and on the rear surface part, friction and viscous resistance are reduced, and the density and the flow velocity of a fluid in contact with the rear surface part are reduced, and thus the propulsion efficiency of the vessel can be improved by increasing the advancing-direction static pressure applied on the rear surface part.SELECTED DRAWING: Figure 3

Description

The present invention relates to a technology for improving the efficiency of propelling a ship.

There are various resistances when moving a ship.

Friction resistance, wave resistance, and viscous resistance are widely known.

In order to reduce frictional resistance, microbubble technology that releases air bubbles into the water that touches the hull, and technology such as the use of a spherical bow (Barbassau) to reduce wave resistance are used. .

Registration number 3671330.

However, when microbubbles are used, there are problems such as a reduction in propulsion efficiency and damage to the propeller itself depending on the amount of the microbubbles and the position where the air is ejected.

Using a spherical bow does not eliminate the waves at all.

Ships are still less efficient than other means of transport.

As in the above-mentioned patent documents, on the front part of the hull, in a monohull ship, a self-made wave is stored in the side part of the temporary hull by installing a wave-dissipating rectifying plate on both sides of the hull. In the catamaran, the outer half of the catamaran is shaped like a hull with a bulge on the inside, parallel to the direction of travel, and temporarily stored between the hulls on both sides. The relative velocity of the fluid that touches the hull between the front and rear of the hull is made different by replacing the wave with the flow velocity.
Alternatively, the flow velocity of the front surface is increased by using a method such as providing a propulsion device in the flow path with the front surface.

By these methods, the static pressure acting around the hull can be reduced at the front portion and increased at the rear portion to obtain the forward force of the hull.

However, this technique is accelerated to some extent even if the flow velocity at the rear surface portion is not exactly the same because it is dragged by the flow velocity increased at the front surface portion.
As a result, it accelerates on the front side, but it is apt.
In the experiment, the following method was reached as to whether there was a method for further increasing the dynamic pressure difference between the front surface portion and the rear surface portion (the static pressure difference affected by the difference).

Also in the present invention, in the front part of the monohull ship, a wave-dissipating rectifying plate is provided on both sides of the hull, and waves are held between the rectifying plate and the hull (FIG. 1). Is made into a parallel vertical plane, and the energy that creates waves as a hull shape with a bulge inside is replaced with the velocity in the flow path in the front (FIG. 2).
Alternatively, the flow velocity at the front surface is increased by using a method such as providing a propelling device in the flow path with the front surface (FIG. 3).

On the other hand, at the point where the surface in contact with the rear surface portion starts, when the air pressurized by the pump is ejected as fine bubbles into the water on the hull side (for example, like microbubbles), the density of the fluid in contact with the rear surface portion is reduced. At the same time, the flow rate is decreased. (Fig. 1, 2, 3)

In addition, the air is blown out not only at the position where the rear surface starts in the hull with the propeller disposed on the front side, but also at the flow path side to which the rear side of the hull's most advanced rear part belongs, or at the front side. A hull with sides parallel to the flow will have an effect if performed at the location where the parallel plane begins, and at all of those locations.

The pressure acting on the front surface portion and the rear surface portion is expressed as (Equation 1) by Bernoulli's theorem.
Front portion Vz; flow velocity ρz; density Psz; static pressure
1/2 × ρz × Vz × Vz; dynamic pressure rear surface portion Vk; flow velocity ρk; density Psk; static pressure
1/2 x ρk x Vk x Vk;
(Expression 1) 1/2 × ρz × Vz × Vz + Psz = 1/2 × ρk × Vk × Vk + Psk

In other words, the difference between the static pressure received by the rear part and the static pressure received by the front part is
Psk−Psz = 1/2 × ((ρz × Vz × Vz) − (ρk × Vk × Vk))
And
The difference in static pressure applied to the front and rear surfaces is the difference between the product of density reduction and the square of the flow velocity due to air mixing. receive.
If 5% of air is mixed, the pressure difference at that time will increase by 14% compared to when no air is mixed.

  Moreover, although the speed of the rear surface portion is also dragged by the flow velocity of the front surface portion, the average flow velocity is naturally lower than that of the front surface portion.

  In addition, the catamaran has the effect of reducing the frictional resistance with the fluid even on the outside due to air mixing, and reducing both the viscous resistance and the frictional resistance on the rear side of the monohull or catamaran.

  The force acting on the front surface portion and the rear surface portion is the sum of the forces acting on all the surfaces, so that the force is large as a whole.

  According to the third aspect of the present invention, by disposing the propulsion device in the flow path to which the front portion belongs, there is no risk of a decrease in propulsion efficiency or damage to the propulsion device due to cavitation.

The top view A and the side view B which added the vertical wave-dissipating rectifying plate parallel to the advancing direction to the monohull ship, and added the blow-out port of the air jet to the position which changes to a rear surface part. The shape of the catamaran is made into a vertical plane parallel to the traveling direction on the outside, and the inside is inflated, the front of the flow path including the rear surface and the front surface of the flow path including the rear surface, and the parallel side begins. The top view A and the side view B of the hull which added the blowing outlet of the air ejection to the place. The top view A and side view B of the hull which added the propulsion device to the flow path which faces the front part of FIG.

A; hull B; wave-dissipating rectifying plate C; wave-dissipating rectifying plate holding member in the case of a monohull ship; support member D of both hulls in the case of a catamaran; wave E; air outlet F; water surface G; Propeller H: Propeller holding member

Claims (3)

In the hull of a ship, a monohull ship is equipped with a wave-dissipating rectifying plate installed vertically in parallel to the traveling direction on both sides of a surface having a projected area forward (below referred to as “front part”) below the water surface of the hull. The self-generated waves are stored on the ship side to increase the flow velocity, immediately before the surface with the projected area behind the hull water surface (hereinafter referred to as the “rear surface portion”) or on the side surface (surface other than the front surface portion and the rear surface portion). A hull that has the function of jetting air pressurized into the water as bubbles from a fine fumarole. In the hull of a ship, in the catamaran, the first half of the hull is parallel to the vertical direction and the vertical plane is used, and as a tip of a structure with a bulge on the inside, waves are stored between the two hulls to increase the flow velocity at the front. A hull having a function of blowing air pressurized to the side and rear surface as bubbles from a fine air outlet into the water. 3. The hull according to claim 1, wherein a propelling device is installed in a flow path having a front portion to increase a flow velocity of the front portion.

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