Solution Of Principles of Naval Architecture, Assignments of Marine Engineering

Download Solution Of Principles of Naval Architecture and more Assignments Marine Engineering in PDF only on Docsity! TASK 1 Part 1 The four principal construction materials used to manufacture vessels are wood, steel, aluminum, and fiberglass. Each material has its advantages and disadvantages, and the types of ships and crafts in which they might be encountered vary. Wood has been used for shipbuilding for centuries, and it is still used today for traditional boats, yachts, and historic replicas. One advantage of wood is its natural buoyancy, which makes it an excellent material for boats that are designed to float. Wood is also relatively easy to work with, making it suitable for custom designs. However, wood requires regular maintenance, including painting and varnishing, to prevent rot and deterioration, and it can be expensive to repair if damaged. Steel is a durable and strong material that is often used for commercial vessels, such as cargo ships, tankers, and container ships. Steel is resistant to corrosion and can withstand heavy loads, making it ideal for large and heavy ships. However, steel is heavy, which can affect a ship's speed and fuel efficiency, and it is susceptible to rust and corrosion if not properly maintained. Aluminum is a lightweight material that is used in the construction of high-speed vessels, such as fast ferries, patrol boats, and pleasure boats. Aluminum is durable, corrosion-resistant, and easy to work with, making it ideal for custom designs. However, aluminum can be expensive, and it is not as strong as steel, making it unsuitable for large and heavy ships. Fiberglass is a popular material used for pleasure boats, such as yachts, sailboats, and speedboats. Fiberglass is lightweight, strong, and easy to maintain, making it a popular choice for recreational boats. Fiberglass boats are also less expensive than wooden boats and can be mass-produced, making them more affordable. However, fiberglass can be brittle and susceptible to cracking and damage, and repairs can be costly. In summary, the choice of construction material depends on the type of vessel and its intended use. Each material has its advantages and disadvantages, and shipbuilders must weigh these factors to determine the best option for their needs. Wood Wooden ships have been in use for thousands of years and are still used today for traditional boats, yachts, and historic replicas. Wood is a versatile material that is easy to work with, making it suitable for custom designs. However, it has several disadvantages, such as: Advantages Disadvantages Natural buoyancy Regular maintenance required Easy to work with for custom designs Expensive repairs if damaged Can have a classic, traditional look Susceptible to rot and deterioration TASK 2 Part 1 Simpson's Rule is a numerical integration method that can be used to calculate the displacement of a vessel. The formula for Simpson's Rule is: Displacement = (L/3) * (A0 + 4A1 + 2A2 + 4A3 + 2A4 + 4A5 + 2A6 + 4A7 + 2A8 + 4A9 + A10) where L is the waterline length and A0 to A10 are the half areas of each section. Using the given values, we can calculate the displacement as: Displacement = (29.5/3) * (0 + 4(3.04) + 2(4.9) + 4(5.02) + 2(4.62) + 4(4.21) + 2(3.8) + 4(3.38) + 2(2.93) + 4(1.79) + 0) Displacement = 441.15 cubic meters To calculate the position of the longitudinal center of buoyancy, we need to find the moment of each half area about a reference point and then sum them up. The reference point is usually the aft perpendicular. Using the given values, we can calculate the moment of each half area as: M1 = 1.7 * 3.04 / 2 = 2.584 M2 = (2.6 + 1.7) * 4.9 / 2 = 9.695 M3 = (3.4 + 2.6) * 5.02 / 2 = 16.964 M4 = (3.4 + 3.4) * 4.62 / 2 = 15.708 M5 = (3.4 + 3.4) * 4.21 / 2 = 14.374 M6 = (3.4 + 3.4) * 3.8 / 2 = 12.88 M7 = (3.4 + 3.4) * 3.38 / 2 = 11.386 M8 = (3.4 + 3.4) * 2.93 / 2 = 9.893 M9 = (2.9 + 3.4) * 1.79 / 2 = 4.6345 The moment of the last section (A10) is zero because the half area is zero. Now we can sum up the moments and divide by the displacement to get the position of the longitudinal center of buoyancy: LCB = (2.584 + 9.695 + 16.964 + 15.708 + 14.374 + 12.88 + 11.386 + 9.893 + 4.6345) / 441.15 LCB = 6.989 meters from the aft perpendicular Therefore, the displacement of the vessel is 441.15 cubic meters and the position of the longitudinal center of buoyancy is 6.989 meters from the aft perpendicular. Part 3 The BM (or the Metacentric Height) of a vessel is a measure of its stability. It is calculated as the distance between the Centre of Gravity (CG) and the Metacenter (M) of the vessel. The formula for calculating BM is: BM = I / (V * KG) where I is the Moment of Inertia of the waterplane about its longitudinal axis, V is the volume of displacement, and KG is the distance between the CG and the Keel. To calculate BM, we need to first calculate I and KG. The Moment of Inertia about the longitudinal axis can be calculated using the formula: I = 1/12 * BWP * L³ where BWP is the Breadth of the Waterplane and L is the Waterline Length. Using the given values, we can calculate BWP as the average of the half breadths at each section: BWP = (0 + 1.7 + 2.6 + 3.4 + 3.4 + 3.4 + 3.4 + 3.4 + 3.4 + 2.9 + 0) / 10 BWP = 2.54 meters Now we can calculate I as: I = 1/12 * 2.54 * 29.5³ I = 1203.3 m⁴ Next, we need to calculate KG, the distance between the CG and the Keel. Since the vessel is symmetrical, the CG is at the midpoint of the waterline, which is 14.75 meters from the aft perpendicular. The Keel is located at the intersection of the Centerline and the Waterplane. Since the vessel has a flat bottom, the Keel is at a depth of 0 meters from the waterline. Therefore, KG = 14.75 - 0 = 14.75 meters. Now we can calculate BM as: BM = I / (V * KG) Using the previously calculated displacement of 441.15 cubic meters, we can calculate V as: V = 441.15 * 1.025 V = 451.84 metric tons Therefore, BM = 1203.3 / (451.84 * 14.75) BM = 0.580 meters So, the BM of the vessel is 0.580 meters.