PROTRACED COUNTERINSURGENCY: CHINESE COIN STRATEGY IN XINJIANG by MAJ J. Scott LaRonde, USA, 95 pages. In 1949, following the conclusion of its revolutionary war against the Chinese Nationalist forces, the People’s Liberation Army (PLA) peacefully occupied China’s western most province of Xinjiang. For nearly sixty years, the PLA has conducted a counterinsurgency against several, mostly Uyghur-led, separatist movements. Despite periods of significant violence, particularly in the early 1950s and again in the 1990s, the separatist forces have not gained momentum and remained at a level one insurgency. Mao ZeDeng is revered as a master insurgent and the father of Fourth Generation Warfare. Strategists in armies worldwide study his writings on revolutionary and guerilla warfare. This monograph concludes that Mao, as well as the communist leaders who followed him, was also successful at waging protracted counterinsurgency. For nearly sixty years, separatist movements in Xinjiang, Tibet, and Taiwan have all failed. This monograph analyzes the conflict in Xinjiang and concludes that the Chinese continue to defeat the separatist movement in Xinjiang through a strategy that counters Mao’s seven fundamentals of revolutionary warfare.

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Approved for Public Release; Distribution is Unlimited

Over the last several decades, several factors have contributed to a major transformation in heat pipe science and technology applications The first major contribution was the development and advances of new heat pipes, such as loop heat pipes (LHPs), micro and miniature heat pipes, and pulsating heat pipes (PHPs) In addition, there are now many commercial applications that have helped contribute to the recent interest in heat pipes For example, several million heat pipes are manufactured each month for applications in CPU cooling and laptop computers Numerical modeling, analysis, and experimental simulation of heat pipes have significantly progressed due to a much greater understanding of various physical phenomena in heat pipes as well as advances in computational and experimental methodologies A review is presented hereafter concerning the types of heat pipes, heat pipe analysis, and simulations

Review and Advances in Heat Pipe Science and Technology

Two-phase forced convective flow in microchannels is promising for the cooling of integrated circuits. There has been limited research on boiling flow in channels with dimensions below 100 /spl mu/m, in which bubble formation and flow regimes can differ from those in larger channels. This work develops single and multi-channel experimental structures using plasma-etched silicon with pyrex glass cover, which allow uniform heating and spatially-resolved thermometry and provide optical access for visualization of boiling regimes. Boiling was observed with less than 5/spl deg/C of super-heating in rectangular channels with hydraulic diameters between 25 and 60 /spl mu/m. The channel wall widths are below 350 /spl mu/m, which minimizes solid conduction and reduces variations in the heat flux boundary condition. Pressure drop and wall temperature distribution data are consistent with predictions accounting for solid conduction and homogeneous two-phase convection.

http://microfluidics.stanford.edu/Publications/Micropumps_Cooling/Zhang%20Meas%20in%20Two%20Phase%20Microchannel%20JMEMS.pdf

Measurements and modeling of two-phase flow in microchannels with nearly constant heat flux boundary conditions

A detailed overview of heat pipes is presented in this paper, including a historical perspective, principles of operations, types of heat pipes, heat pipe performance characteristics, heat pipe limitations, heat pipe frozen startup and shutdown, heat pipe analysis and simulations, and various applications of heat pipes. Over the last several decades, several factors have contributed to a major transformation in heat pipe science and technology . The first major contribution was the development and advances of new heat pipes, such as loop heat pipes, micro and miniature heat pipes, and pulsating heat pipes. In addition, there are now many new commercial applications that have helped contribute to the recent interest in heat pipes, especially related to the fields of electronic cooling and energy. For example, several million heat pipes are now manufactured each month since all modern laptops use heat pipes for CPU cooling. Numerical modeling, analysis, and experimental simulation of heat pipes have also significantly progressed due to a much greater understanding of various physical phenomena in heat pipes, as well as advances in computational and experimental methodologies.

http://m.thermalfluidscentral.org/journals/index.php/Heat_Pipes/article/view/360/362

Heat pipes: review, opportunities and challenges

Flat miniature heat pipes (FMHP's) are shown to be very promising in the cooling of electronic component systems. This investigation presents a detailed experimental and theoretical analysis on maximum heat transfer capabilities of two copper-water FMHP's with diagonal trapezoidal micro capillary grooves and one copper-water FMHP with axial rectangular micro capillary grooves. Maximum heat flux on the evaporator wall of the 120-mm long axial grooved heat pipe, with a vapor channel cross-sectional area of approximately 1.5 x 12 mm 2 and rectangular grooves of dimensions 0.20 mm wide by 0.42 mm deep, exceeded 90 W/cm 2 in the horizontal orientation and 150 W/cm 2 in the vertical orientation. Theoretical prediction of the capillary limitation in the horizontal orientation agreed reasonably well with the experimental data.

Flat Miniature Heat Pipes With Micro Capillary Grooves

A detailed mathematical model is developed that describes heat transfer through this liquid films in the evaporator of heat pipes with capillary grooves. The model accounts for the effects of interfacial thermal resistance, disjoining pressure, and surface roughness for a given meniscus contact angle. The free surface temperature of the liquid film is determined using the extended Kelvin equation and the expression for interfacial resistance given by the kinetic theory. The numerical results obtained are compared to existing experimental data. The importance of the surface roughness and interfacial thermal resistance in predicting the heat transfer coefficient in the grooved evaporator is demonstrated. 17 refs., 5 figs., 2 tabs.

Heat Transfer During Evaporation on Capillary-Grooved Structures of Heat Pipes

Heat transfer in the inverted meniscus type evaporator at high heat fluxes

A detailed mathematical model of low-temperature axially grooved heat pipes (AGHP) is developed in which the fluid circulation is considered along with the heat and mass transfer processes during evaporation and condensation. The results obtained are compared to existing experimental data. Both capillary and boiling limitations are found to be important for the flat miniature copper-water heat pipe, which is capable of withstanding heat fluxes on the order of 40 W/cm 2 applied to the evaporator wall in the vertical position. The influence of the geometry of the grooved surface on the maximum heat transfer capacity of the miniature AGHP is demonstrated.

Thermal Characteristics of Conventional and Flat Miniature Axially Grooved Heat Pipes

A mathematical model of the evaporating liquid-vapor meniscus in a capillary slot has been developed. The model includes two-dimensional steady-state momentum conservation and energy equations for both the vapor and liquid phases, and incorporates the existing simplified one-dimensional model of the evaporating microfilm. The numerical results, obtained for water, demonstrate the importance of accounting for the fluid flow in calculating the effective evaporative heat transfer coefficient and the superheat of the vapor over the liquid-vapor meniscus due to the heat transfer from the heated wall. With higher heat fluxes, a recirculation zone appears in the vapor near the heated wall due to the extensive evaporation in the thin-film region of the liquid-vapor meniscus.

D. Khrustalev

Papers

Flat Miniature Heat Pipes With Micro Capillary Grooves

Heat Transfer During Evaporation on Capillary-Grooved Structures of Heat Pipes

Heat transfer in the inverted meniscus type evaporator at high heat fluxes

Thermal Characteristics of Conventional and Flat Miniature Axially Grooved Heat Pipes

Fluid flow effects in evaporation from liquid-vapor meniscus