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ρ is the air density (typically 1200 g1.2 kg/m³ at room temperature).
v is the airflow velocity (m/s), which can be estimated from the fan's specifications.
L is a characteristic length (0.250m)
μ is the dynamic viscosity of air (0.01918 g1.918E-5 kg/ms)
Nu = 0.023 ⋅ Re0.8 ⋅ Pr0.33 ⋅ (L/D)0.5 (Nusselt’s number for airflow parallel to fins)
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Q = ((0.023 ⋅ ρvL/μ0.8 ⋅ Pr0.33 ⋅ (L/D)0.5 ⋅ k)/L)Atotal(Tobject−Tambient) (heat transferred)
Q = 27.2885 ⋅ ΔT
Sources:
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