Yu Matsutomi

Facility Development for Testing of Wave Rotor Combustion Rig

A Wave Rotor Combustion Rig (WRCR) is under development by a team including Purdue University, Rolls-Royce (LibertyWorks

Experimental Investigation on the Wave Rotor Constant Volume Combustor

A wave rotor constant volume combustor was designed and built as a collaborative work of Rolls-Royce, Indiana University-Purdue University Indianapolis (IUPUI), and Purdue University. The experiment was designed to operate at rotational speeds of up to 4,200 rpm with air mass flow rates of approximately 18 lbm per second. Initial tests were conducted at 2,100 rpm with ethylene as fuel. The rig was operated with different fuel injection schemes to investigate operational characteristics of the combustor. Successful combustion and pressure gain were achieved over a range of operating conditions.

Pressure Gain Combustor Component Viability Assessment Based on Initial Testing

A review of recent testing has been performed to assess the viability of a wave-rotorbased pressure-gain combustor. Tests accomplished in 2009 at the Purdue Zucrow lab on the Wave Rotor Combustor Rig (WRCR) provide basic information on the combustion processes achievable in a wave rotor passage. During a 30 day test period, 34 successful tests were completed, the longest of which was a 3-second firing was completed which totaled nearly 2,000 individual combustion events. Analysis of the results indicated stable combustor operation. The operability of the device is assessed regarding stability and combustion speeds. Agreement with predicted operation is examined. Potential for successful integration into a gas turbine as a replacement of a conventional combustor is addressed.

Analysis of Deflagrative Combustion in a Wave-Rotor Constant-Volume Combustor

Initial testing of the wave-rotor constant-volume combustor (WRCVC) exhibited rapid deflagrative combustion of rich ethylene mixtures, with some evidence of ignition prior to alignment with ignition gas injector. Test data is analyzed to understand ignition and combustion behavior using a transient gas dynamics and combustion simulation code. Flow of hot gases from passages of the WRCVC and the ignition gas injector through the clearance gap between the rotor and the stationary end plates may be implicated as an occasional source of ignition. A representative test case is examined for a comprehensive discussion on ignition initiation location, ignition delay time, and flame propagation speed through the passages.

Studies on Valveless Pulse Detonation Engines

An unsteady lumped parameter analysis tool is developed to analyze the operational characteristics of valvesless PDE. The model divide s the fluid system into multiple control volumes and applies conservation equations to analyze transient characteristic of flow. The mass flow rates between control volumes are treated as a flow through an orifice. The fluid properties are represented with a set of differenti al equations and it is numerically integrated over time. In order to apply the unstead y lump parameter analysis, detonation propagation into a detonation tube must be carefull y modeled with three methods, detonation propagation model, constant volume combustion model and empirical model. The model is used to analyze the operational charac teristics of the Purdue valveless PDE. Parametric studies of component geometries, as well as operating conditions are performed systematically.

Experimental Velocity Profiles in the Cap Shock Pattern of a Thrust Optimized Rocket Nozzle

The cap shock pattern is observed in the plumes of over-expanded thrust optimized rocket nozzles at the low pressure ratios that typically occur during start-up and shut-down transients. This shock pattern is related to restricted shock separation, and associated flow transitions can result in damaging side loads. Instantaneous 2D planar velocity measurements are obtained here with hydroxyl tagging velocimetry, in which molecular tags are written into the flow by laser photo-dissociation and tracked by laser-induced fluorescence. Measured velocity profiles are compared with numerical simulation and show promise as a detailed validation tool.

Entropy Considerations on Integration of Pressure Gain Combustors

The primary goal of this study is to understand the issues associated with integrating the pressure-gain combustion device to a conventional steady state gas turbine engine. The loss of performance due to a poor integration method can be critical. Two types of transitional methods are examined using entropy-based models. An accumulator based transition has obvious loss due to sudden area expansion, but it c an be minimized by utilizing the gas dynamics in the combustion tube. An ejector type transition has potential to achieve performance beyond the limit specified by a single flow path Humphrey cycle. The performance of an ejector was discussed in terms of apparent entropy and mixed flow entropy. Through an ideal ejector, the apparent pa rt of entropy increases due to the reduction in flow unsteadiness, but entropy of the mixed flow remains constant. The method is applied to a CFD simulation with a simple manifo ld for qualitative evaluation.

Investigation of the Cap-Shock Pattern in a Thrust-Optimized Rocket Nozzle

The cap-shock pattern from both experiments and simulations are presented. By axisymmetrical calculations, the cap-shock pattern at a nozzle pressure ratio = 20 is simulated as exhibited by an experimental visualization using hydroxyl tagging velocimetry. It is confirmed that the steady shock structures are driven by an Mach reflection with an internal shock. Furthurmore, the evolution of a cap-shock pattern was investigated experimentally and numerically using shadowgraphic images for a throttling process.

Flight Performance Comparison of Pulse Detonation and Ramjet-Propelled Vehicles

This paper outlines a model that was developed to c ompare the performance of a pulse detonation engine (PDE) powered vehicle with the performance of a ramjet powered vehicle in the low supersonic speed range. Comparing the Isp between the two propulsion systems predicts that the PDE should exceed the efficiency of the ramjet throughout the low supersonic range of speeds. However, fuel flow results produced by this model suggest that the performance advantage enjoyed by the PDE becomes negligible beyond a particular Mach number and that at speeds beyond this Mach number the ramjet is the more efficient choice. Intake air flow requirements causing significant drag are shown to be the source of the diminishing PDE efficiency at higher Mach numbers.

Biannular Airbreathing Nozzle Rig Facility Development at Purdue University

The Biannular Airbreathing Nozzle Rig (BANR) facility has been developed at Purdue University for the purpose of evaluating the performance of airbreathing propulsion nozzle concepts. The facility has been made operational, and a plug nozzle designed for a supersonic business jet (SSBJ) mission has been extensively tested over a wide range of conditions. Diagnostic tools of the facility include a suite of pressure instrumentation, a traversing rake system for measuring temperatures and pressures in nozzle exhaust plumes, and a six-axis force measurement system. The facility has been demonstrated to operate reliably and consistently at all investigated test conditions, and conditions entering the test article were seen to be uniform in each stream for all tests. Performance data from the plug nozzle, including discharge and force coefficients have been obtained for a variety of cold flow and hot-fire conditions.