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Boiling heat transfer characteristics greatly depend on bubble dynamics behaviors. Whereas the influence of bubble dynamics on boiling heat transfer mechanism under the vertical heating wall condition is scarce. In this work, lattice Boltzmann (LB) method is implemented to investigate the relationship between bubble dynamics and boiling heat transfer on the vertical heating wall. Bubble nucleation, growth and departure processes under different wettability conditions are systematically studied. The results demonstrate that the vapor phase covering the vertical surface increases at a greater contact angle. The bubble detachment becomes difficult, leading to the reduction of bubble volume. Because of the interaction of buoyancy force and bubble growth under the vertical heating wall, physical properties of the three-phase contact line and bubble dynamics show strong coupling characteristics. In addition, the heat flux on the hydrophilic and hydrophobic surfaces can be enhanced by 98% and reduced by 75% compared to that on the neutral surface. [ABSTRACT FROM AUTHOR]

The sensitivity calculation of airborne gamma-ray spectrometer (AGS) is usually performed by on-ground or in-flight calibration. However, both methods are cost-ineffective or not permissive, especially for artificial radioisotopes with short half-lives. Alternative to these methods is the Monte Carlo simulation, which has been widely applied over the last few decades. The greatest challenge to the practicability of the Monte Carlo simulation in the AGS calibration is its low computational efficiency for ensuring an acceptable reliability. This article proposes a hybrid numerical method for the sourceless AGS calibration by combining the deterministic point-kernel approach and the Monte Carlo simulation. This method is not only more efficient than the source-based calibration by an empirical method, but also independent of the source availability for on-ground or in-flight calibration. For a given soil test model, AGS sensitivities calculated by this hybrid method agree well with those obtained from the empirical method for the in-flight calibration. [ABSTRACT FROM AUTHOR]