Aerodynamic and Thermal Characteristics of a Hot Jet in Parallel Flow

This paper presents an experimental investigation of the aerodynamic and thermal characteristics of a round jet of hot air, injected through a nozzle into a parallel air flow, simulating a hot streak. Experiments were performed by imposing the same total pressure, established by means of a five-hole probe, for the mainstream and the jet at nozzle exit. Time-averaged temperatures at different points over planes downstream of the nozzle exit section were measured by thermocouple rakes. Experimental data, presented in a non-dimensional form, provide a representation not correlated to individual maximum jet temperature and Reynolds number, in the respective fields of variation. The attenuation of the hot jet strength is reported as a function of the normalized axial coordinate for the various operating conditions considered. Results obtained for the hot jet discharged into a parallel flow are compared with data obtained for the hot jet spreading into stagnant air.