Paddleducks
Paddler Modelling => Paddlewheels/Drive Systems => Topic started by: Tomas Krejci on October 14, 2012, 07:28:04 AM
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abstract:
KDRK –„ paddle propulsion steering complex “ by SEATECH
1 > http://wheelships.ru/
2 > http://wheelships.ru/index.php/joomla-license
Construction in that paddle steering wheel-drive system (DRC) allows changing the direction of thrust vector by changing the ratio of the speed and direction of rotation wheel. As shown in the figure below, the maximum torque of the ship can be achieved by changing the direction of rotation paddle wheel at full speed in the opposite direction.
In practical applications have mentioned steering paddle wheel propulsion system far more robust construction than conventional paddle wheel with tilting blades.
Despite a slightly lower efficiency against side wheels with tilting blades ,makes the wheels according to the invention, much more constant pressure, which is advantageous especially in the case where the above system is used to drive the pusher.
Impellers system KDRK have welded a unified structure that can be built at the factory and as a finished block installed on the ship. Accuracy requirements do not exceed the requirements for existing production in the shipbuilding sector..
In recent years there was developed a number of projects of small vessels with these power units. Weight of these units is lighter than the wheels with paddles with tilting blades of the same dimensions, but if you do not require amplification for navigation in ice. The structure is managed and technologically reliable for simple maintenance.
This propeller systém DRC, against the ship propeller allows control and repair works without docking the ship.
DRK dvizhitelno -rulevyi komplex propulsion steering complex
KDRK kolesnyi dvizhitelno- kolesnyi komplex paddle propulsion steering complex
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A fascinating link Tomas, thanks for sharing it with us.... I only wish I could understand Russian :(
Regards
Eddy
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Hi Eddy,
I think, Uncle Google can help a little.
I am building Lulonga model with such modified paddlewheels.
I am preparing at least a few lines about the construction, too for this my favorite server.
For information .. I have a photos of model building on the website> www.tomarack.rajce.net <with some next photos.
I want to proof that unorthodox construction , in a somewhat simplified form. Mainly I wonder if the model will be really skillful.
please.. how can I change my avatar?
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Hi PD's...& thank you Thomas for sharing the WEB build.....those angular bladed wheels are interesting :hammer
When we think about the angled blades :thinking......do they not improve straight line directional stability? :squareone
With respect to ....." how can I change my avatar?" ...easy
1. log on to your profile
2. select modify profile
3. select system profile
4. select upload avatar
5. then browse the source location....just remember to keep the file size within limitations .........Derek :beer
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Thanks, Derek,
sorely there are few informations in the article only. Web links written in English unfortunately again refer to pages in Russian Cyrillic.
I'll try to translate some of the more information that are available at present in the article. I have to do triple translation for accuracy .. from Russian into Czech(as my mother language) and finally to English , in order to be factually accurate translation ... still an interesting experience...
greetings Tom
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II.part of the article*
Please forgive me for imperfection of translation thank you TK
*
To increase effectiveness in the use KDRK for passenger ships, paddle wheels can be in the form of truncated cones on the outer edge of a smaller diameter than the inner edge (near the center line ships - ДП see picture). In this case, the vane have axial helical shape with an optimal angle of entry into the water at the edge of the outer rim of the wheel and the optimum angle for the rear edge of the blade outlet of water in the inner circumference of the wheel (for an assumed speed of the ship.)
KDRK when used for pushers, to increase propulsive efficiency of the drive frame can be fitted with a paddle wheel device for directing the output current of water with adjusting the approach angle and its lifting above the water surface.
For use in extreme conditions (eg ships, which are expected to cruise in the ice, or in icebreakers) Are produced massive frame to the wheels of high-strength materials
*Traction and performance characteristics achieved from paddle system DRK
* From practice it is known that specific traction coefficient (coefficient of tensile strength) of impellers (paddle wheels) in the improvement of resistance against the movement is increased 1.5 to 2 times.
Having the same power the boat with drive unit DRK will have faster acceleration , compared with a ship that has a propeller or thrusters drive unit.
*
Increase in length of the blades, or increase the wheelbase powerplant in addition to improving manageability causes an increase traction and improve traction characteristics thanks DRK entrainment of water from the ship's side and compression of water flow. To reduce losses and increase the speed of expelled water flow (and thus the speed of the vessel) the wheel DRK are constructed in the form of a truncated cone .
Water particles trapped in the vane wheel torque */stroke/ are moving along the surface of the blade toward the axis of the vessel DP( ДП). The acceleration gain gradually as the diameter of the paddle wheel and thus peripheral speed of the blades increases proportionally from the sides toward the axis of the ship.
increasing rate of excretion of water jet reduces the formation of water waves behind paddlewheel and lifting water from paddle at output. To this also helped the axial screw-shaped blade.
in all modes, the motion of the vessel ensures maximum traction performance through optimal values DRC immersion paddle wheels through a system of raising and lowering the frame with propulsion unit . When designing sternwheel pusher there rectifiers of the beam can be used, which increase the traction coefficient to 25%
Besides the technical advantages DRC paddle these boats will have also environmental benefits, manifested a milder impact on flora and fauna in the environment, because the particle velocity of water flowing through the paddle wheels there is an order of magnitude lower than in the ship's screw. Shallow draft and ability to self-release from shallow running boat KDRK reduce demand on the volume of dredging the bottom while maintaining the seaworthiness of waterways.
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wheel own drive is done through an a double, or triple chain, as can be seen in the relatively dim picture ( the chain is placed on the platform next to the wheel).
In this case
Paddle wheel drive ........... electromechanical
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Work wheel DRK in shallow waters, foul waters and ice conditions
3.part of the article
Absence of vulnerable elements - turning (tilting) paddle blades and classic rudder blades (feathers) ensures to the paddle DRK increased reliability of operation on the ultimate shallow water up as well as the fact that in case of get stuck on the ground in the shallows ,the whole paddle unit can be lowered to the bottom, and the ship under its own power digs out .
The design allows a paddle DRK can be made so strong that these aggregates may be used as a device for breaking ice. For this case, the wheels, designed symmetrically to the axis of the vessel DP and having a separate drive are manufactured in the form of full helical cutter of high tensile steel of sufficient thickness, with internal reinforcing ribs *
Sleeve (shell) construction of such paddle wheels provides high strength and stiffness and acceptable weight (almost the same weight as the paddle wheels with rotary steel blades). It should be noted that the efficiency of movement at forward speed in the ice wheel for the ship will be higher, as this will be observed the following positive effects:
1. The wheel working at the edge of the ice creates a underpressure, which helps breaking off pieces of ice in the strike edge of the wheel. (in the place where edge of blade hits the ice)***
2. The ice breaks mainly due to shock deformation at the edge of the cut, rather than bending stress (as the wheels have shape of milling cutters), thanks to what the consumption of energy for breaking the ice decreases because on the skid strenght of ice is 5 times lower than the bend strength.
3. Chunks of ice are trapped by wheel blades and along with a large body of water are released and thrown sideways of the channel under the edge of the ice.
4. The ship moves in a clean channel, the frictional resistance of ice, forming up to 15% of the total frictional resistance for icebreakers with traditional structures, is practically zero (practically nonexistent).
5.For movement in heavy ice due to strokes paddle wheels on ice occur vibration, this effect again results in further reduction of friction resistance of the front stem post on ice.When entering the open water the vibration disappears automatically.
6.Unlike traditional icebreakers, crushing ice, the ship can cross the ice jams on rivers, move between pieces of ice and on the surface of solid ice. It can move forward and stern forward too without fear of breaking the DRK
While for vessels with screw drive and jet propulsion the interactions with ice and crushed ice leads to deterioration of seaworthiness and reduce traction power ,for a paddle DRK this interaction reduces slippage and thus increases the efficiency of the drive.
Icebreaker equipped with paddle DRC can crush ice by controlled way, to move forward as the bow or stern, to move forward and backward, turn around on the spot in the ice, with a own draft of about 20% of the diameter paddle wheel.
Reliability is ensured by the DRC that the paddle wheels on impact with an obstacle (the edge of the ice field, stranded) rolled out on it and extinguish the energy of impact, preventing damaging stresses in the structure. Using active device for crushing ice makes inertial and shape characteristics of the vessels secondary and less important.
. It is expected that an icebreaker with paddle DRK on the same ice throughput may have against the traditional icebreaker 1.5-2 times less power and displacement.
This means that the cost of building and operating costs reduced by about half.
I believe , it is nearly the whole article translated ...
Tom
uff
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My sincere thanks for taking the time to translate all of the Russian text Tomas.
It's good to see that the "old" technology still has a place in the modern world!
Regards
Eddy
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some abbreviations for the first article >wheelships.ru<
All linear measurements are in meters !!
Длина габаритная, м Length o.a.(max)
Длина по КВЛ, м … Length at WL
Ширина габаритная, м Breadth o.a. (max)
Ширина по КВЛ, м … Breadth at W.L.
Высота габаритная, м Height max
Высота борта, м … depth (hull height)
Осадка по КВЛ, м … draught designed
Длина расчетная, Calculated length (length designed)
Ширина расчетная, м Breadth design,m
Осадка расчетная, м Draft design, m
Мощность ЭУ, кВт 100+60 power unit kW (100+60)
Экипаж, чел. …. crew
Скорость, км/ч … speed km/hour
Пассажировместимость, чел. …40 passenger capacity
Автономность, сут. …..6 autonomy , days..
Привод гребных колес Paddle wheel drive
гидравлический .. hydraulic
электромеханический ... electromechanical
Водоизмещение .. displacement
Грузоподъемность,(200T) Carrying capacity, 200 ton (tonnage)
Скорость на глубокой воде, км/час Speed in deep water, km / h
Скорость, км/час при толщине льда: Speed, km / h- with an ice thickness:
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Hi Eddy,
I was pleased to contribute to our interesting server.
The documents for the construction of ships placed on this website help me very much, especially in the construction of the model Lulonga. I'm trying to delete my small debt...
eventual questions if I can and be able to, I will answer
greetings
Tom
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My thanks as well Tomas.
So, who's going to have theirs finished for Paddlers Day next year?
kiwi
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Hi guys,
Please also check out the post from> towboat joe <> herringbone wheels <
Aug 7 / 2007
Tom
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Hi,
as I saw here in forum, there was another, sorry, the same article , about a year ago..
We called .. walk late in the day ..
> http://www.paddleducks.co.uk/smf/index.php?topic=5485.msg29423#msg29423 <
nevertheless I found article from Popular mechanics < nov. 1947 and some next photos
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Unfortunately, the original article at the above mentioned address
1 > http://wheelships.ru/
2 > http://wheelships.ru/index.php/joomla-license
is not more available.
At your disposal is only my old translation.
kismet ...
Tom
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:D Hello ;
Hello TOMAS !!!!
:vacation
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Greetings Tomas...do you realise that this publication ...." Popular mechanics < nov. 1947 " ...is 69 years old :hehe ...
So do you now tell our members that you could read these articles at 2 years of age?.......
Derek... :beer
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Hi Derek,
after all , today it is possible to do everything - such an time machine, for example ... :P
I corrected this post, this time I think correctly.
Anyway, all the best for the new year 2017 - and especially a lot of success in building model boats to you also to the members of our forum.
Greetings
Tom