{"id":20436,"date":"2018-12-02T14:03:21","date_gmt":"2018-12-02T14:03:21","guid":{"rendered":"http:\/\/sitepourvtc.com\/?page_id=20436"},"modified":"2023-02-15T08:12:57","modified_gmt":"2023-02-15T08:12:57","slug":"example-convection-problem-with-solution","status":"publish","type":"page","link":"https:\/\/sitepourvtc.com\/nuclear-engineering\/heat-transfer\/convection-convective-heat-transfer\/example-convection-problem-with-solution\/","title":{"rendered":"Example – Convection – Problem with Solution"},"content":{"rendered":"
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Example – Convection – Cladding Surface Temperature<\/h2>\n

\"Convection<\/a><\/strong><\/p>\n

Cladding<\/strong> is the outer layer of the fuel rods, standing between the reactor coolant<\/strong> and the nuclear fuel<\/strong> <\/a>(i.e., fuel pellets<\/strong>). It is made of corrosion-resistant material with a low absorption cross-section for thermal neutrons<\/a>, usually zirconium alloy<\/strong>. Cladding<\/strong> prevents radioactive fission products from escaping the fuel matrix into the reactor coolant and contaminating it. Cladding constitutes one of the barriers in the \u2018defense-in-depth <\/b>\u2018 approach; therefore, its coolability<\/strong> is one of the key safety aspects.<\/p>\n

Consider the fuel cladding of inner radius r<\/strong>Zr,2<\/sub><\/strong> = 0.408 cm<\/strong> and outer radius r<\/strong>Zr,1<\/sub><\/strong> = 0.465 cm<\/strong>. Compared to fuel pellet, there is almost no heat generation in the fuel cladding (cladding is slightly heated by radiation<\/a>). All heat generated in the fuel must be transferred via conduction<\/strong><\/a> through the cladding, and therefore the inner surface is hotter than the outer surface.<\/p>\n

Assume that:<\/p>\n