Comparison of h for water between TMMHP and SMMHP
In Figure 17 and 18, h values of water at both SMMHP [6] and TMMHP for different inclinations can be compared. The h values at TMMHP are very high and sinusoidal throughout the heat input range while the h at SMMHP begins with very low values and grows too slow with the increasing heat input. In addition, the highest h value is recorded at 90o for SMMHP and at 45o for TMMHP. However, the trajectories at both SMMHP and TMMHP clearly indicate the limit of h with the increasing heat input. Since all the operating and test parameters remain the same at both single and two-metal micro heat pipe, the variability of heat conductivity as well as their designed orientation in TMMHP are considered to be the only initiators for greater h values.
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Figure 17. Convec. HT coeff. of water in SMMHP[6) at dif. inclns. Figure 18. Convec. HT coeff.of water at TMMHP at dif. inclns.