As a reference, consider the Meredith effect, which applies (applied) in the construction of the P-51 Mustang radiator.
From the linked Wiki site:
The Meredith effect occurs when air flowing through a duct is heated
by a heat-exchanger or radiator containing a hot working fluid such as
ethylene glycol. Typically the fluid is a coolant carrying waste heat
from an internal combustion engine.1
For the effect to occur, the duct must be travelling at a significant
speed with respect to the air. Air flowing into the duct meets drag
resistance from the radiator surface and is compressed due to the ram
air effect. As the air flows through the radiator it is heated,
raising its temperature slightly and further increasing its volume.
The hot, pressurised air then exits through the exhaust duct which is
shaped to be convergent, i.e. to narrow towards the rear. This
accelerates the air backwards and the reaction of this acceleration
against the installation provides a small forward thrust.[2] The air
expands and decreases temperature as it passes along the duct, before
emerging to join the external air flow. Thus, the three processes of
an open Brayton cycle are achieved: compression, heat addition at
constant pressure and expansion. The thrust obtainable depends upon
the pressure ratio between the inside and outside of the duct and the
temperature of the coolant.1 The higher boiling point of ethylene
glycol compared to water allows the air to attain a higher temperature
increasing the specific thrust.
If the generated thrust is less than the aerodynamic drag of the
ducting and radiator, then the arrangement serves to reduce the net
aerodynamic drag of the radiator installation. If the generated thrust
exceeds the aerodynamic drag of the installation, then the entire
assemblage contributes a net forward thrust to the vehicle.
It's important to note that the primary purpose of this construction was to counteract the drag of the exposed radiator. It's certainly unlikely to generate sufficient thrust to power an aircraft.