India's aircraft carrier design may have major defects.
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lonelyman
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i already pointed out what fucking Indians idiots are
but these ship design know-nothing keyboard warrior idiots say big waves expected because its not car cruising on road
well, they have enough ppt experts, mouth cannon warriors
GamoAccu
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What ship is this?
INS Vikrant (Lemon)
jaybird
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Someone wrote a long article about it with pictures and explanation. Not sure how true this is though. The website with ad warning. So, don't want to link to original article. But you can search it yourself if you want to.
The Vikrant sea trial keeps "kowtow", and the Indian carrier-based pilot is in big trouble
2021-11-02 12:07 HKT
On October 24, 2021, the "Made in India" aircraft carrier Vikrant, which was eager for Indians, finally conducted its second sea test in the eastern Arabian waters. It is said that the test was "a complete success." However, a video tracked by a helicopter showed an interesting phenomenon: this medium-sized aircraft carrier with a standard displacement of 40,000 tons was running up and down at sea, as if it was "kowtow" all the way!
Like other countries, the Indian aircraft carrier chose a calm day for the second sea trial. The purpose is to test the reliability of the ship's power system and high-speed navigation capabilities. From the video screen, the sea is relatively calm and the wave height is below 1 meter. Occasionally, white waves are seen, which belongs to the second-level sea state.
For an aircraft carrier with a total length of 262 meters, the natural conditions are perfect enough. Why does the naval ship's navigation stir a series of waves?
The direct cause of this phenomenon is that the aircraft carrier swayed in the course of sailing, referred to as pitching.
When the sea conditions are bad, the ship will sway at sea, or swing left and right, or wave back and forth. Even if it is a 10,000-ton drive, it will inevitably be thrown up and fall between the crests and valleys, creating dangers.
When the US nuclear-powered aircraft carrier sails under high sea conditions, all carrier-based aircraft must be fixed, no people can stand on the deck, and the aircraft's take-off and landing activities will stop. This is because violent ups and downs and longitudinal shaking not only bring risks to the flight, but may also cause the crew to fall into the sea.
However, the trouble encountered by the Vikrant is far more than that. An aircraft carrier still kowtows three times in the second sea state, which means that even if the weather is calm, the pilot of the Indian carrier aircraft may be killed on the deck when the ship is on the ship. .
Where is the problem? Let us try to find the reason from the design and manufacture of the Vikrant.
In the long manufacturing process of the domestically-made aircraft carrier in India, a careful Indian netizen found a very special detail: this aircraft carrier did not have a bulbous bow below the waterline!
Unlike the huge ball on the front of the US aircraft carrier, the bow of the USS Vikrant extends to the bottom of the ship like a knife. Some friends said that this would have the least resistance when sailing, and others said it would help break through thick ice.
There are no icebergs in the Indian Ocean. The main task of the Vikrant is to take care of the homes and turn the Indian Ocean into an "Indian Ocean." invalid. So, can it really be faster without the bulbous bow?
When a ship sails on the water, its speed is related to the power and resistance of the water. The greater the resistance, the slower the speed. Water resistance is roughly divided into wave resistance and water friction resistance, and wave resistance includes wave breaking resistance and wave making resistance. Small boats can reduce the resistance by reducing the contact surface with water as much as possible; but large ships can only reduce the resistance by changing the streamline of the bottom of the ship.
When the ship is sailing at high speed, the bow cuts the water current and squeezes the water around. At this time, a bow wave is generated on the side of the ship. The vortex generated by the bow wave in turn acts on the hull, pushing the bow upward on the one hand. , While squeezing the side of the ship, producing larger and larger waves.
By adding a bulbous bow to the bow to change the pressure distribution along the hull, the protruding ball will generate a water wave before the hull. The trough of this wave is just in phase with the crest generated by the hull, so the two waves cancel each other out. It can overcome the wave making resistance to the greatest extent, thereby increasing the sailing speed of the ship or saving fuel when sailing at the same high speed.
It should be noted that the use of bulbous bow making waves to offset the bowing waves is only useful for large ships sailing at high speeds. If the length of the waterline of the ship is less than 15 meters, or the speed of the ship is not fast, only a few or more than a dozen knots, the bulbous bow will not only not reduce the resistance, but will also drag down the navigation due to the increase of the wave breaking resistance and the area of the infiltration zone.
There used to be many ultra-large container ships, bulk carriers and oil tankers that also used huge bulbous bows in their designs. However, the latest cargo ships have gradually eliminated bulbous bows and switched to traditional blade-shaped bows. This also shows that The bulbous bow has limited effect on low-speed ships.
The other two reasons why large commercial ships cancel the bulbous bow are: the bulbous bow is more complicated in design and construction, and the cost is much higher. After all, lowering the cost is equivalent to making more money; ships with bulbous bows are not so flexible in steering. In collisions, most of the bulbous noses under the waterline are damaged, and the ship is often hindered when anchoring. In order to prevent the heavy and large iron anchor from hitting the hull, the windlass equipment needs to be re-arranged, and the anchor lip that protrudes from the hull must be designed.
Unlike military ships, the speed of aircraft carriers is often around 30 knots, and some ships are even higher than 30 knots. When the ship sails at such a high speed in the water, the wave resistance will account for 40-50% of the ship's total resistance. This is a factor that must be considered.
Another important function of the bulbous bow is to increase pitch damping and reduce the longitudinal sway of the ship.
The ship pitches during navigation. On the one hand, the front and lower wave resistance lifts the bow upward, and the other reason is that the center of gravity of the ship is not on the same vertical line as the center of drifting.
The waterline profile of a military ship is usually a long and narrow bullet shape. Ship designers and manufacturers need to be extra careful to counterweight the ship so that its center of gravity coincides with the center of drift. If the two are not on the same plumb line, the ship will inevitably pitch as long as the surface of the water fluctuates. This should be the case on the Vikrant.
Some destroyers or frigates will set up automatically controlled fins on the outside of the hull to reduce the sway amplitude, but the aircraft carrier is too large and generally will not be equipped with fin stabilizers, and it is impossible to control the attitude through the ballast tanks inside the ship. The construction of modern aircraft carriers not only tests a country's design capabilities, but also places extremely high demands on the entire industrial system.
The aircraft carrier is not built in a swimming pool, you have to let it go to the sea to rule the king and let the carrier-based aircraft take off and land from above. If an aircraft carrier vacillates in second-level sea conditions, who can expect it to participate in operations in higher sea conditions?
The high-speed navigation of warships requires a bulbous bow to increase speed and maintain stability. This is a common sense problem that all ship designers understand. As the design leader of the Vikrant, the Indian Naval Design Bureau certainly understands the importance of the bulbous bow. However, the bulbous bow of an aircraft carrier does not just hit a ball in front of it casually. This involves complicated fluid mechanics and needs to be determined through scientific calculations and repeated experimental verification.
The real reason why Vikrant did not install the bulbous bow lies in its manufacturer. Because the manufacture of the bulbous bow is extremely complicated, you need to bend a few centimeters of high-strength steel plate into the required three-dimensional curved surface and then weld it into a sphere. There can be no mistakes in the process, otherwise it will cause serious consequences. The Cochin Shipyard lacks the necessary manufacturing equipment and technical personnel, and the designers are happy to save trouble. After all, the blade-shaped bow is a steel plate welded to the end, which saves money and everyone has less trouble.
However, in the future, Indian naval pilots will drive carrier-based aircraft to take off and land on this constantly "kowtow" aircraft carrier, which is a test of skill and luck. If an accident occurs, the landing gear will break, or the aircraft will be destroyed. This is really no joke!
The Vikrant sea trial keeps "kowtow", and the Indian carrier-based pilot is in big trouble
2021-11-02 12:07 HKT
On October 24, 2021, the "Made in India" aircraft carrier Vikrant, which was eager for Indians, finally conducted its second sea test in the eastern Arabian waters. It is said that the test was "a complete success." However, a video tracked by a helicopter showed an interesting phenomenon: this medium-sized aircraft carrier with a standard displacement of 40,000 tons was running up and down at sea, as if it was "kowtow" all the way!
Like other countries, the Indian aircraft carrier chose a calm day for the second sea trial. The purpose is to test the reliability of the ship's power system and high-speed navigation capabilities. From the video screen, the sea is relatively calm and the wave height is below 1 meter. Occasionally, white waves are seen, which belongs to the second-level sea state.
For an aircraft carrier with a total length of 262 meters, the natural conditions are perfect enough. Why does the naval ship's navigation stir a series of waves?
The direct cause of this phenomenon is that the aircraft carrier swayed in the course of sailing, referred to as pitching.
When the sea conditions are bad, the ship will sway at sea, or swing left and right, or wave back and forth. Even if it is a 10,000-ton drive, it will inevitably be thrown up and fall between the crests and valleys, creating dangers.
When the US nuclear-powered aircraft carrier sails under high sea conditions, all carrier-based aircraft must be fixed, no people can stand on the deck, and the aircraft's take-off and landing activities will stop. This is because violent ups and downs and longitudinal shaking not only bring risks to the flight, but may also cause the crew to fall into the sea.
However, the trouble encountered by the Vikrant is far more than that. An aircraft carrier still kowtows three times in the second sea state, which means that even if the weather is calm, the pilot of the Indian carrier aircraft may be killed on the deck when the ship is on the ship. .
Where is the problem? Let us try to find the reason from the design and manufacture of the Vikrant.
In the long manufacturing process of the domestically-made aircraft carrier in India, a careful Indian netizen found a very special detail: this aircraft carrier did not have a bulbous bow below the waterline!
Unlike the huge ball on the front of the US aircraft carrier, the bow of the USS Vikrant extends to the bottom of the ship like a knife. Some friends said that this would have the least resistance when sailing, and others said it would help break through thick ice.
There are no icebergs in the Indian Ocean. The main task of the Vikrant is to take care of the homes and turn the Indian Ocean into an "Indian Ocean." invalid. So, can it really be faster without the bulbous bow?
When a ship sails on the water, its speed is related to the power and resistance of the water. The greater the resistance, the slower the speed. Water resistance is roughly divided into wave resistance and water friction resistance, and wave resistance includes wave breaking resistance and wave making resistance. Small boats can reduce the resistance by reducing the contact surface with water as much as possible; but large ships can only reduce the resistance by changing the streamline of the bottom of the ship.
When the ship is sailing at high speed, the bow cuts the water current and squeezes the water around. At this time, a bow wave is generated on the side of the ship. The vortex generated by the bow wave in turn acts on the hull, pushing the bow upward on the one hand. , While squeezing the side of the ship, producing larger and larger waves.
By adding a bulbous bow to the bow to change the pressure distribution along the hull, the protruding ball will generate a water wave before the hull. The trough of this wave is just in phase with the crest generated by the hull, so the two waves cancel each other out. It can overcome the wave making resistance to the greatest extent, thereby increasing the sailing speed of the ship or saving fuel when sailing at the same high speed.
It should be noted that the use of bulbous bow making waves to offset the bowing waves is only useful for large ships sailing at high speeds. If the length of the waterline of the ship is less than 15 meters, or the speed of the ship is not fast, only a few or more than a dozen knots, the bulbous bow will not only not reduce the resistance, but will also drag down the navigation due to the increase of the wave breaking resistance and the area of the infiltration zone.
There used to be many ultra-large container ships, bulk carriers and oil tankers that also used huge bulbous bows in their designs. However, the latest cargo ships have gradually eliminated bulbous bows and switched to traditional blade-shaped bows. This also shows that The bulbous bow has limited effect on low-speed ships.
The other two reasons why large commercial ships cancel the bulbous bow are: the bulbous bow is more complicated in design and construction, and the cost is much higher. After all, lowering the cost is equivalent to making more money; ships with bulbous bows are not so flexible in steering. In collisions, most of the bulbous noses under the waterline are damaged, and the ship is often hindered when anchoring. In order to prevent the heavy and large iron anchor from hitting the hull, the windlass equipment needs to be re-arranged, and the anchor lip that protrudes from the hull must be designed.
Unlike military ships, the speed of aircraft carriers is often around 30 knots, and some ships are even higher than 30 knots. When the ship sails at such a high speed in the water, the wave resistance will account for 40-50% of the ship's total resistance. This is a factor that must be considered.
Another important function of the bulbous bow is to increase pitch damping and reduce the longitudinal sway of the ship.
The ship pitches during navigation. On the one hand, the front and lower wave resistance lifts the bow upward, and the other reason is that the center of gravity of the ship is not on the same vertical line as the center of drifting.
The waterline profile of a military ship is usually a long and narrow bullet shape. Ship designers and manufacturers need to be extra careful to counterweight the ship so that its center of gravity coincides with the center of drift. If the two are not on the same plumb line, the ship will inevitably pitch as long as the surface of the water fluctuates. This should be the case on the Vikrant.
Some destroyers or frigates will set up automatically controlled fins on the outside of the hull to reduce the sway amplitude, but the aircraft carrier is too large and generally will not be equipped with fin stabilizers, and it is impossible to control the attitude through the ballast tanks inside the ship. The construction of modern aircraft carriers not only tests a country's design capabilities, but also places extremely high demands on the entire industrial system.
The aircraft carrier is not built in a swimming pool, you have to let it go to the sea to rule the king and let the carrier-based aircraft take off and land from above. If an aircraft carrier vacillates in second-level sea conditions, who can expect it to participate in operations in higher sea conditions?
The high-speed navigation of warships requires a bulbous bow to increase speed and maintain stability. This is a common sense problem that all ship designers understand. As the design leader of the Vikrant, the Indian Naval Design Bureau certainly understands the importance of the bulbous bow. However, the bulbous bow of an aircraft carrier does not just hit a ball in front of it casually. This involves complicated fluid mechanics and needs to be determined through scientific calculations and repeated experimental verification.
The real reason why Vikrant did not install the bulbous bow lies in its manufacturer. Because the manufacture of the bulbous bow is extremely complicated, you need to bend a few centimeters of high-strength steel plate into the required three-dimensional curved surface and then weld it into a sphere. There can be no mistakes in the process, otherwise it will cause serious consequences. The Cochin Shipyard lacks the necessary manufacturing equipment and technical personnel, and the designers are happy to save trouble. After all, the blade-shaped bow is a steel plate welded to the end, which saves money and everyone has less trouble.
However, in the future, Indian naval pilots will drive carrier-based aircraft to take off and land on this constantly "kowtow" aircraft carrier, which is a test of skill and luck. If an accident occurs, the landing gear will break, or the aircraft will be destroyed. This is really no joke!
GamoAccu
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Last edited:
FairAndUnbiased
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it really has no bulbous bow. Wow. Ok.
GiantPanda
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Indians are not worry because the Vikrant is expected to launch aircraft only in sea state 0 and 8 knots.
Who is the designer for that ship? He needs to be sack!
Indiots had to do one thing right and they screwed it up. Now they've given the Indian Navy a ship with a vagina rather than a ball sack.
@siegecrossbow next time better to toss the Indians into the ocean.
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Blacklight
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Thats not how things work in India, they will give him a medal for this.
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