Full exam for Heat and Mass Transfer Scambio Termico e di Massa in the Energy Engineering degree programme at Politecnico di Milano. The document covers: Politecnico di Milano – A.Y. 2025–2026 Master Programme in Energy/Nuclear Engineering Heat and Mass Transfer Examination – 12 January 2026 Surname: Name: Student ID number: Grade 1 -. . . . . . . . . /10 2 -. . . . . . . . . /10 3 -. . . . . . . . . /10 Total . . . . . . . . .
Full exam for Heat and Mass Transfer Scambio Termico e di Massa in the Energy Engineering degree programme at Politecnico di Milano. The document covers: Politecnico di Milano – A.Y. 2025–2026 Master Programme in Energy/Nuclear Engineering Heat and Mass Transfer Examination – 12 January 2026 Surname: Name: Student ID number: Grade 1 -. . . . . . . . . /10 2 -. . . . . . . . . /10 3 -. . . . . . . . . /10 Total . . . . . . . . .
Import quality: text was extracted directly from the original document.
Representative passages recognised in different parts of the material. The full extracted text remains available to search, while this compact preview makes the page easier to read.
Politecnico di Milano – A.Y. 2025–2026 Master Programme in Energy/Nuclear Engineering Heat and Mass Transfer Examination – 12 January 2026 Surname: Name: Student ID number: Grade 1 -. . . . . . . . . /10 2 -. . . . . . . . . /10 3 -. . . . . . . . . /10 Total . . . . . . . . . /30 The time available is 2.5 hours . Only the material provided as Supplementary Material may be used. No textbooks, notes, or electronic devices are allowed. The maximum score is 30/30. At the end of the exam, this text must be submitted with the numerical results written next to each question , and only one protocol sheet (four written pages) with the detailed solution must be handed in. Exercise 1 (10 points) An isothermal (Tc = 85 ◦C) silicon chip of widthW = 20 mm on a side is soldered to an aluminum heat sink (λ = 180 W /m K) of equivalent width. The heat sink has a base thickness ofLb = 3 mm and an array of 11 rectangular fins, each of lengthLf = 15 mm. An air flow atT∞ = 25 ◦C and with a velocity ofu∞ = 8.9 m/s is maintained through the channels formed by the fins and a cover plate. The fin spacing isδ = 1.8 mm. The solder joint has a thermal resistanceR′′ t,c = 6 · 10−5 m2 K/W. An adiabatic fin tip condition may be assumed, and airflow along the outer surfaces of the heat sink may be assumed to provide a convection coefficient equivalent to that associated with airflow through the channels. The air properties should be evaluated atT∞. Find: 1. the mean convective heat transfer coefficient, assuming an almost uniform fin temperature 2. the power dissipated to the air 3. the temperature at the base of a fin and the effectiveness of a single fin Accounting for the increase in air temperature as it flows through the heat sink, find: 4. the outlet temperature of the air exiting each channel…
First page of the document.
