Table 5 Measurement uncertainty for relevant parameters/variables
From: Spray cooling characteristics of nanofluids for electronic power devices
Parameters/variables | System error | Random error | Combined error | |
|---|---|---|---|---|
Test surface | Length (L) | ±0.05% | ±0.94% | ±0.94% |
Width (W) | ±0.05% | ±0.88% | ±0.88% | |
High (H) | ±0.5% | ±4.58% | ±4.61% | |
Area (A) | ±0.1% | ±1.82% | ±1.82% | |
Test chamber | Length (L) | ±0.02% | ±1.05% | ±1.05% |
Width (W) | ±0.02% | ±1.27% | ±1.27% | |
High (H) | ±0.04% | ±3.20% | ±3.2% | |
Distance between thermocouples (Δx) | ±0.2% | ±1.17% | ±1.19% | |
Measurement parameters and variables | Surface temperature (Tw) | ±3.87% | ±7.40% | ±8.35% |
Power (P) | ±1.91% | ±3.02% | ±3.57% | |
Heat flux (q″) | ±2.01% | ±4.84% | ±5.24% | |
Volumetric flow rate (Q) | ±1.60% | ±2.74% | ±3.17% | |
Mass flux (G) | ±1.70% | ±4.56% | ±4.87% | |
Pressure drop (ΔP) | ±0.18% | ±1.42% | ±1.43% | |
Dimensionless group/heat transfer data | Weber number (We) | ±1.33% | ±2.58% | ±2.9% |
Reynolds number (Re) | ±1.72% | ±5.03% | ±5.32% | |
Heat transfer coefficient (h) | ±5.88% | ±12.24% | ±13.58% | |