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 – 01 July 2026 Surname: Name: Student ID number: Grade 1 -. . . . . . . . . /15 2 -. . . . . . . . . /15 Total . . . . . . . . . /30 The time available is 3
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 – 01 July 2026 Surname: Name: Student ID number: Grade 1 -. . . . . . . . . /15 2 -. . . . . . . . . /15 Total . . . . . . . . . /30 The time available is 3
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 – 01 July 2026 Surname: Name: Student ID number: Grade 1 -. . . . . . . . . /15 2 -. . . . . . . . . /15 Total . . . . . . . . . /30 The time available is 3 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 no more than two protocol sheets (eight written pages) containing the detailed solution must be handed in. Problem 1 (15 points) In a paper-mill drying process, a thin sheet of paper slurry (water–fiber mixture) leaves a roll and moves with a constant velocityus = 5.0 m/s. Radiant heaters maintain the sheet surface atTs = 310 K while evaporation occurs from both the upper and lower surfaces of the sheet. The surrounding air is atT∞ = 290 Kand p = 1 atm, with relative humidityϕ∞ = 0.30. The analysis refers to a sheet segment of lengthL = 1.0 min the direction of motion. The radiant heaters may be modeled as blackbodies atTH = 1000 K. They are two identical black strips, one above and one below the sheet. Each strip is parallel to the sheet, very long in the transverse direction, located at a distanceH = 0.50 mfrom the corresponding sheet surface and centered with respect to the sheet segment. The slurry surface is diffuse and opaque and has the following spectral reflectivity: ρλ = 0, λ < 5 µm, 0.50, 5 µm ≤ λ < 9 µm, 0.90, λ ≥ 9 µm. The surface exchanges radiation with large surroundings atT0 = T∞. The air properties can be assumed equal to those of dry air, while the slurry is assumed to have water properties. Find:…
First page of the document.
