top of page
Search

solucionario transferencia de calor holman j p rapidshare







































The transfer of heat is a function that allows energy to move from hot thing with high temperature to the surrounding gas, with low temperature. The transfer of heat can be powered by many mechanisms including convection, conduction, radiation and evaporation. An everyday example of this process is the evaporation of sweat on your skin. When you are sweating or exerting yourself physically, your body produces heat which is transferred into the surrounding air via evaporation. Heat can also be transferred by convection when gases are heated up and rise due to their buoyancy in warmer air mass with lower density than the source object's surroundings. In this case, it is the hot gas that transfers heat to the surrounding colder air. Convection is possible because heat can move from a warmer gas to a cooler gas. In case of absorption of radiation the process involves transfer of heat from an object to another one by emitting infrared rays towards it. In case of emission of radiation the process involves all objects around us continuously emitting electromagnetic waves in a spectrum visible or invisible to human eye. These waves are absorbed by objects and matter which causes them to absorb some amount of energy depending on their thermal conductivity and their temperature through conduction, convection and evaporation. The process of absorption of radiation occurs in times of full moon or during summer time when more light is emitted into the surroundings of earth by the sun. This process also occurs due to the reflectiveness that some objects have towards these rays. Examples of these are water which reflects most visible light, trees which reflect infrared waves and ice which absorbs most of them. Heat emitted by objects is carried to another object or material by convection. Other types of transfer include evaporation and conduction. Convection is a transfer where heat moves from one particle, material or gas to another particle, material or gas through natural phenomenon such as buoyancy, gravity among others. In the process of convection, heat naturally moves from a hotter object or material to a colder one. This occurs for example in a room heated by the sun. The air inside the room will be heated and rise towards the ceiling as it becomes less dense than the cold air outside. The process of conduction is one where heat moves from one material to another by direct physical contact such as through solids, liquids and gases. The two materials may be touching or separated by other materials such as metals which are good conductors for conduction of energy/heat/thermal energy flux. The thermal energy flux is expressed as thermal conductivity which is a material's ability to conduct heat. A material having a high thermal conductivity is considered to conduct heat easily. The process of conduction can also occur when two materials are in direct contact with eachother without any physical obstruction. Due to this, the transfer of heat is more efficient. This occurs in the case of insulation like the one used for constructing houses. The process of conduction can also occur by radiation through infrared rays emitted towards an object by its surroundings. Convection is a process where heat moves from one particle, material or gas to another particle, material or gas through natural phenomenon such as buoyancy, gravity among others. eccc085e13

2 views0 comments

Recent Posts

See All

Comments


bottom of page