Table 4 Related variables and parameters used in the study
From: Spray cooling characteristics of nanofluids for electronic power devices
Experimental parameters | |||
|---|---|---|---|
Heat spreader area (cm2) | 4 | ||
Nozzle to target surface distance (mm) | 25 | ||
Nozzle diameter, dj (μm) | 500 | ||
Working medium | DI water | ||
Pressure difference, ΔP (kPa) | 18.6 | 32.4 | 53.1 |
Volumetric flow rate, Q (ml/s) | 2.63 | 3.57 | 4.76 |
Mass flux, G (kg/cm2s) | 6.58 × 10−4 | 8.93 × 10−4 | 11.90 × 10−4 |
Droplet diameter, d 32 (μm) | 299.8 | 259.7 | 228.5 |
Weber numbera, We = ρu m 2 d 32/σ | 140.2 | 223.9 | 350.3 |
Ohnesorge numbera, Oh = We0.5/Re | 0.0038 | 0.0036 | 0.0034 |
Reynolds numbera, Re = ρu 0 d j/μ | 7784.7 | 10572.8 | 14097.1 |
Saturation temperature, T sat (°C) | 100 | ||
Saturation pressure, P sat (kPa) | 101 | ||
Degree of subcooling, ΔT sub (°C) | 75 | ||
Characterization of the heated surface | |||
Material | Cu | ||
Thermal conductivity (W/mK) | 401 | ||
Thermal expansion coefficient (×10−6/K) | 17 | ||
Specific heat capacitance (J/gK) | 0.385 | ||
Density (kg/m3) | 8,920 | ||
Melting point (°C) | 1,084 | ||
Roughness (μm) | 2 ~ 3 | ||