No, in the universe radiation heat transfer is by far the largest transfer.
Whether convection is the main type of heat transfer or not depends on the specific situation.
liquids
convection
The convection
Conduction AND convection, only the latter requires a fluid.
Whether convection is the main type of heat transfer or not depends on the specific situation.
There are 3 main Heat Transfer Mechanisms: Conduction, Convection and Radiation.
Convection.
convection
Convection.
liquids
convection
The convection
Conduction AND convection, only the latter requires a fluid.
Conduction.
convection
convection