Figure 1.
Figure 2.
Figure 3.
Figure 4.
Figure 5.
Figure 6.
Figure 7.
Figure 8.
Figure 9.
Figure 10.
UT2
| Greek letters | |
|---|---|
| β | Liquid void fraction |
| δ | Liquid layer thickness |
| ε | Emissivity |
| ρ | Density |
| σ | Surface tension (for ethanol: 22.8x10-3 N/m @T=20°C) |
| σr | Stefan-Boltzmann constant |
| ν | Kinematic viscosity |
| μ | Dynamic viscosity |
UT1
| A | Area |
| Ac | Dispersion constant (for ethanol: 2.2x10-21 J) |
| c | Accommodation coefficient |
| Dh | Hydraulic diameter |
| f | Fin thickness |
| fRe | Poiseuille number |
| h | Heat transfer coefficient |
| hfg | Latent heat of vaporization |
| k | Thermal conductivity |
| L | Length |
| mj | Mass flux rate through liquid-vapor interface |
| M | Molecular weight |
| N | Number of the channels |
| P | Pressure |
| Q | Heat load |
| q | Heat flux |
| R | Gas constant |
| Reff | Effective thermal resistance |
| rc | Radius of meniscus |
| T | Temperature |
| TR | Turn-down ratio |
| u | Velocity in x-direction |
| U | Wind speed |
| V | Volume |
| W | Width |
| w | Half width of the channel |
| wr | Half meniscus surface area per unit length |
UT3
| Subscripts and superscripts | |
|---|---|
| amb | Ambient |
| b | Groove base |
| c | Condenser |
| e | Evaporator |
| g | Non-condensable gas |
| i | Inactive region |
| in | Input |
| l | Liquid phase region |
| lv | Liquid-vapor interface |
| max | Maximum |
| min | Minimum |
| out | Output |
| r | Reservoir |
| s | Solid wall |
| surface | Surface |
| t | Total |
| v | Vapor phase region |
| w | Wick structure |
| 0 | Reference value |
Specifications of the two planar heat pipes_
| Brass Heat Pipe (BHP) | Liquid Crystal Polymer Heat Pipe (LCP-HP) | |
|---|---|---|
| Length (cm) | 27.94 | 5.08 |
| Width (cm) | 13.97 | 5.08 |
| Thick (cm) | 1.27 | 0.8334 |
| Wall thickness (mm) | 3.175 | 3.175 |
| Grooves type | Triangular | Rectangular |
| Grooves dimensions | ||
| 72 grooves per plate | 32 grooves per plate |
Properties of brass and CoolPoly® E2 Liquid Crystal Polymer_
| Brass | Liquid Crystal Polymer | |
|---|---|---|
| Density (g/cm3) | 8.7 | 1.6 |
| Thermal conductivity | 109 | 20 |
| (W/mK) | ||
| Tensile Modulus (Gpa) 100 | -125 | 24.3 |
| Tensile Strength (Mpa) | 200 | 80 |
| Flexural Modulus (Gpa) | 39 | 32.3 |
| Flexural Strength (Mpa) | 235 | 139 |