We use cookies to create the best experience for you. Keep on browsing if you are OK with that, or find out how to manage cookies.
Nobody downloaded yet

Riblets and Tripwires and their role in reducing drag over underwater aerofoils - Essay Example

Comments (0)
Riblets and Tripwires, and their Role in Reducing Drag Over Underwater Aerofoils by Your name Subject Tutor name University Date Riblets and Tripwires, and their Role in Reducing Drag over Underwater Aerofoils Introduction Riblets and tripwires are widely explored and documented structures that have a huge potential for use in drag reduction technology…
Download full paper
Riblets and Tripwires and their role in reducing drag over underwater aerofoils
Read TextPreview

Extract of sample
Riblets and Tripwires and their role in reducing drag over underwater aerofoils

Download file to see previous pages... Their optimal specifications, mechanism of functioning and potential applications for drag reduction over underwater aerofoils have also been dealt with. Riblets and tripwires In case of underwater vehicles, fluid mechanical drag (hydrodynamic drag) reduces the speed with which they travel through water. For a specific limit of engine power, the maximum speed that can be attained by the vehicle is drastically reduced due to the formation of eddies very close to the surface of the vehicle. Apart from this, another source of hydrodynamic drag is the development of pressure drag due to laminar flow at the boundary layers. Riblets can be used to reduce the formation of eddies near the surface of the vehicle, while tripwires can be used to reduce the pressure drag and induce turbulence at the boundary layers. Riblets: These are minute grooves, longitudinally placed on the surface of a vehicle or airfoil, and are in alignment with the direction of flow. They “have been shown by Walsh and Lindemann [1984] at the National Aeronautics and Space Administration (NASA) and Reidy and Anderson [1988] at the Naval Ocean Systems Center (NOSC) to produce as much as 8 percent turbulent flow drag reduction on flat plates”.1 Studies on “fully submerged axisymmetric bodies”1 conducted by Beauchamp and Philips [1986 and 1987], have shown that the use of riblets reduces skin friction by seven percent.1 Tripwires: Tripwires, also known as turbulators, are thin wires that are attached at the hull of a vehicle or at the nose of a submarine or aircraft. These are used to “trip” or disturb the boundary layer and introduce turbulence, thereby reducing pressure drag. These are “one of the oldest and most used methods of turbulence stimulation”.2 1. Mechanism To comprehend the mechanism of functioning of riblets and tripwires, it is essential to understand the types of drag imposed on a vehicle and the process of their induction. The total drag experienced by a body, includes a combination of pressure and friction. The frictional drag can be reduced by using smooth surfaces. However, studies have shown that this form of drag is further reduced with the help of riblets. The boundary layer of flow around a vehicle can be distinguished into three parts, “a relatively small viscous sublayer, the middle buffer layer and the logarithmic layer”.3 The riblets that are used to reduce drag “extend into the buffer layer. With this kind of riblets a drag reduction of about 8-10%” has been achieved. This is because the riblets restrain the movement of eddies, which are prevented from coming very close, within 50 microns, to the surface of the aircraft or vehicle. “By keeping the eddies this tiny distance away, the riblets prevent the eddies from transporting high-speed fluid close to the surface, where it decelerates and saps the aircraft's momentum”.4 To reduce the pressure drag over a vehicle, tripwires are used. Pressure drag occurs when there is a “lack of pressure recovery on the back of the body, due to separation of the flow around the body”.5 This results from laminar flow in the boundary layer around the vehicle. By using tripwires, it is possible to induce turbulence in this laminar layer, thereby reducing pressure drag. 2. Optimal Specifications The extent of drag reduction is found to increase with the size of riblets. However, for very ...Download file to see next pagesRead More
Comments (0)
Click to create a comment
Underwater Communication
The Different Types of Underwater Communication Diver Underwater Communications One of the most common uses of underwater communication technologies is for the divers. There are types of underwater communication gadgets used by the divers. These include the tools used to communicate to the surface and the tools used to communicate with another diver.
3 Pages(750 words)Essay
What role do NGOs play in reducing poverty in developing countries
After the formulation of United Nations in 1945 the term Non Governmental Organization came into existence.These organizations have many roles which include promoting rights of a specific faction of society,promoting basic services like education and health,fighting laws and rules that are against poor or a particular group and helping government fighting diseases
7 Pages(1750 words)Essay
Deep Green Underwater Kite
The importance given to environment in the recent years, however, restricts or criticizes certain advanced technologies. Some technologies, directly or indirectly, affect human beings and other living creatures in the world. For the increasing importance to the ethical, moral, social and health outcomes of every technology and advancement manufacturers are continuously finding ways which are less harmful for the environment and nature.
5 Pages(1250 words)Essay
Strategic Decision Making Underwater Hotel
So, the problem is how the information and concepts were structured. The graphical representations of the elements and the way they interact should have been presented in a more clear and concise manner. For example, the link between the value proposition and customer segment was clearly established.
6 Pages(1500 words)Essay
Respond paper over the president Obama speech on reducing gun violence
The signing provided the widest measures in gun control witnessed in the US since the Federal Assault Weapons Ban that was enforced in 1994 and expired in 2005. This was necessitated, among others, by the Newtown, Connecticut, mass shootings. The plan by President Obama aims to not only reinstate and enhance the ban on assault weapons, but will necessitate, for all sales of guns, a criminal background check; restore the limit on 10 rounds for ammunition magazines; get rid of bullets capable of piercing armor; lift the freeze put on research into gun violence; necessitate four executive actions that will avail information to the background check systems on individuals deemed to be dangerous;
3 Pages(750 words)Essay
Role of Economic Development in Reducing the Poverty Rate
The main focus in this paper is on theoretical underpinning of the economic growth concept. The essay also focuses on interrelationships between the rate of growth and the poverty rate. Scholars have defined economic growth as the increase in the value rated in goods and services produced by countries in relation to their economic activities.
8 Pages(2000 words)Essay
Calculated Versus Observed Underwater Sound Speed
The report will present information that was ascertained in other research such as the studies at Dart Observatory at the Brittania Royal Naval College. It will analyze the influences on sound velocity, of salinity and temperature, and show how researchers find results and make determinations based on those analyses and calculations.
6 Pages(1500 words)Essay
Reducing Obesity
The author of this essay aims to analyze the health problems caused by obesity, factors the leads to it and how to prevent. The adult obesity rate in Europe is at least 20 percent. Low-income groups and countries are affected most from obesity. Obese people are vulnerable to multiple health problems.
13 Pages(3250 words)Essay
Breathing underwater
Things seemed normal and perfect from the outside but the only person that knew otherwise was Nick, who tried his best to fool everyone around with his calm demeanor. Life for Nick in the affluent area of South Florida was
4 Pages(1000 words)Essay
The History of drag racing
I however do not agree with the idea of risking people lives for the sake of having fun. I also think the development of drag racing was a risky activity taken too far. The thirty-minute
3 Pages(750 words)Essay
Let us find you another Essay on topic Riblets and Tripwires and their role in reducing drag over underwater aerofoils for FREE!
Contact us:
Contact Us Now
FREE Mobile Apps:
  • About StudentShare
  • Testimonials
  • FAQ
  • Blog
  • Free Essays
  • New Essays
  • Essays
  • The Newest Essay Topics
  • Index samples by all dates
Join us:
Contact Us