GABISAN, MARY JUDY A. BSNAME-5 ME 415 (Heat transfer and Thermal System) Assignment #1 What are the thermal conductivity of at least 10 different materials used in marine application such as, steel, aluminium, GRP, etc? 1. Aluminium Alloys: The most often used Al-alloys used in shipbuilding are the 5083 type for plates and 6082 for extrusions. These alloys are reliable in marine service as well as during manufacture. It has estimated that the selection of Al-Mg (Aluminium-Magnesium) type alloys brings a potential for at least 10% lower costs in respect of the heat-treatable, and appears favourable after a total estimation for applicability in shipbuilding Aluminium 5083 is known for exceptional performance in extreme environments. 5083 is highly resistant to attack by both seawater and industrial chemical environments. Alloy 5083 also retains exceptional strength after welding. It has the highest strength of the non-heat treatable alloys but is not recommended for use in temperatures in excess of 65°C. Thermal Conductivity=121 W/m.K 2. Aluminium alloy 6082 is a medium strength alloy with excellent corrosion resistance. It has the highest strength of the 6000 series alloys. Alloy 6082 is known as a structural alloy. In plate form, 6082 is the alloy most commonly used for machining. As a relatively new alloy, the higher strength of 6082 has seen it replace 6061 in many applications. The addition of a large amount of manganese controls the grain structure which in turn results in a stronger alloy. Thermal Conductivity=180 W/m.K 3. Mild steel or cast steel watertight doors are fitted below the water line, which prevents flooding of the compartments when shut while providing adequate strength in the case of emergencies. Thermal Conductivity= 44.97- 64.86 W/m.K 4. Ship propellers are constructed from copper alloys such as brass. Thermal Conductivity = 150 W/m.K 5. Bronze propellers Thermal Conductivity = 85 W/m.K 6. The fitting of zinc plates in the way of bronze propellers and other immersed fittings being used as sacrificial anodes is common practice in shipbuilding. Thermal Conductivity = 116 W/m.K 7. Modern anodes are based on alloys of zinc, aluminium, or magnesium which have undergone many tests to examine their suitability; high purity zinc anodes are also used. Sacrificial anodes are fitted with the hull and also often in ballast tanks as well. Thermal Conductivity = 156 W/m.K 8. GRP (glass reinforced plastic) is a composite of tough resilient, durable plastic resin, and glass fibres of remarkable strength. Polyester Resins: The Resins most commonly used in GRP are unsaturated polyesters dissolved in styrene. The polyesters are produced by reacting various organic acids (usually phthalic or maleic anhydrides) with an alcohol such as propylene glycol or ethylene glycol. Thermal Conductivity = 0.3 W/m.̊C 9. Glassfibre - The Glass used commonly for GRP is a calcium-alumina borosilicate with an alkali content of less than one per cent. It is commonly known as ‘E’ type glass, since it was originally developed for use in electrical insulation systems. Thermal Conductivity = 1.35 W/m.K 10. Copper-nickel alloys were developed specifically for seawater service over five decades ago, initially for condensers and piping systems. Their overall suitability has since been confirmed by continuing use in these and other marine applications. 90-10 Cu-Ni has a higher iron content. Thermal Conductivity = 40 W/m.K REFERENCES: https://www.marineinsight.com/guidelines/what-materials-are-used-for-building-ships/ https://www.aalco.co.uk/datasheets/Aluminium-Alloy-5083-0-H111-Sheet-and-Plate_149.ashx https://www.aalco.co.uk/datasheets/Aluminium-Alloy-6082-0-Sheet_146.ashx https://www.engineersedge.com/properties_of_metals.htm https://www.ecfibreglasssupplies.co.uk/topic/GuidetoGlassReinforcedPlastics https://www.azom.com/properties.aspx?ArticleID=764 https://www.copper.org/applications/marine/cuni/properties/physical/ https://www.tibtech.com/conductivite.php?lang=en_US
