certain unavoidable but undesirable increase in 
temperature. High pressure air delivered to 
combustion chamber receives heat from the 
combustion of fuel and experiences a rise in 
temperature. The fuel flow is limited so that 
the turbine inlet temperature is within limits 
which can be tolerated by the turbine structure. 
The combustion takes place at relatively con- 
stant pressure and initially low velocity. Heat 
addition then causes large increases in gas vol- 
ume and flow velocity.