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Heat pipes lose heat transfer the longer they are in length (shorter heat pipes provide better overall thermal conductivity)
good for solar car application considering space constraints and need to minimize weight
Heat Pipes conventionally use an evaporation and condensation end to convert liquid to vapor
the liquid (typically water) has to be maintained above freezing point and below vapor condensation point (important detail when considering application)
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Heat pipes can be designed in various shapes
provides valuable flexibility when designing. However, the design of heat pipe will definitely impact its maximum efficiency/maximum power transport capacity (big need for ANSYS)
Heat pipes are typically made with these materials (most used to least used):
Copper ---> Aluminum ----> Stainless Steel === Titanium (need to consider weight vs energy benefits for solar car)
Heat Wick Structures are structures that are within the heat pipe that transport fluid from condensed areas. Essentially, it separates fluid traveling back to heat source and the vaporized fluid. Most popular three:
Sintered Wicks: linked walls of (typically) copper within the heat pipe that are baked at high temperatures. Deal with high heat flux and gravity forces very well, giving them versatility when designing the heat pipe
Screen/Braided Wicks: designed like a screen door and are used to make thin heat pipes (will reduce weight). Less expensive than sintered wicks but not as efficient with heat flux
Grooved Wicks: cheapest option as they are part of the heat pipe. Less flexibility as can only operate in gravity neutral situations (condenser on same level as evaporator)
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Evaporation portion has to be at or above condenser area to work
Heat pipes have incredibly long lifespans (up to 20 years) when operating between limitation ranges