The NexGen burner: Non-Reacting gaseous and spray dynamics

Abstract

This paper reports the results of a comprehensive investigation to identify turbulent multiphase fluid dynamics through the NexGen burner used for fireworthiness certifications by the Federal Aviation Administration. The burner geometry consists of a draft tube, a stator to swirl the incoming air, a turbulator that is placed immediately downstream of the stator to increase the turbulence intensity of the swirling flow, and a burner cone that exhausts into the atmosphere. A Delavan type-W fuel nozzle, attached downstream of the turbulator injects Jet A into the burner cone, where it mixes with the turbulent swirling air, vaporizes and subsequently burns. The operating conditions consist of air and fuel mass flow rates of 0.0384 kg/s and 2.5 Gph at room temperature and pressure conditions. In this paper, we report on non-reacting fluid dynamics; the reacting flow analysis will be presented in a subsequent manuscript. To systematically analyze the flow configuration, three calculations are conducted. First, to validate our large eddy simulation-based framework, a case without the burner cone is conducted—our results are in reasonable agreement with experimental measurements. In the second configuration, to isolate the effect of liquid injection on turbulent flow physics, simulations are conducted with the burner cone but without fuel spray. Detailed analyses are conducted, including identification of flow structures, swirl generation, and the turbulent kinetic energy budget. Finally, Jet A is injected into the burner, and the spray and gaseous flow fields are quantified and compared with the flow structures developed without spray injection.