Aerodynamic Model Study of Marine Gas Turbine Exhaust Cooling

Autor: C J Marquand
Rok vydání: 1978
Předmět:
Zdroj: Journal of Ship Research. 22:123-129
ISSN: 1542-0604
0022-4502
DOI: 10.5957/jsr.1978.22.2.123
Popis: Problems such as the overheating of aerials by hot exhaust gas have been experienced by the Royal Navy on their new generation of gas turbine powered ships. Model tests indicate that the temperature trajectories from square, rectangular and clusters of circular exhausts may be correlated on the same basis as single circular exhausts, by substitution of a characteristic dimension in a simple temperature-decay equation. Plume temperature measurements show that lower temperatures can be obtained by enhancing the vortex activity in the plume, thereby causing more ambient air to be entrained, and that this can be achieved by using exhausts other than circular, where the plume drag is increased. Plume temperatures may also be reduced by introducing air entrainment into the uptake itself. Here it is important to ensure that the low-momentum entrained cooling air surrounds the hot exhaust jet as it leaves the uptake. It is then easily deflected into twin vortices in the downstream plume and these entrain ambient air. Air-entraining exhausts produce at least 20 percent lower maximum temperature difference ratio values in the downstream hot gas plume than more conventional exhausts.
Databáze: OpenAIRE