<P> Heat convection occurs when bulk flow of a fluid ( gas or liquid ) carries heat along with the flow of matter in the fluid . The flow of fluid may be forced by external processes , or sometimes ( in gravitational fields ) by buoyancy forces caused when thermal energy expands the fluid ( for example in a fire plume ) , thus influencing its own transfer . The latter process is often called `` natural convection '' . All convective processes also move heat partly by diffusion , as well . Another form of convection is forced convection . In this case the fluid is forced to flow by use of a pump , fan or other mechanical means . </P>
<P> Heat convection occurs when bulk flow of a fluid ( gas or liquid ) carries heat along with the flow of matter in the fluid . The flow of fluid may be forced by external processes , or sometimes ( in gravitational fields ) by buoyancy forces caused when thermal energy expands the fluid ( for example in a fire plume ) , thus influencing its own transfer . The latter process is often called `` natural convection '' . All convective processes also move heat partly by diffusion , as well . Another form of convection is forced convection . In this case the fluid is forced to flow by use of a pump , fan or other mechanical means . </P>
the process by which a mechanical device is used to move a fluid or gas to transfer heat
the process by which a mechanical device is used to move a fluid or gas to transfer heat
forced convection
forced convection