Subscale Engine Exhaust Containment System Phase 2 Hydrogen

Subscale Engine Exhaust Containment System Phase 2: Hydrogen Wave Heater Overview Presenter: Laurence de Quay, NASA/SSC June 28, 2017 1

Subscale Engine Exhaust Containment System Phase 2: Hydrogen Wave Heater Wave Rotor History • First patent 1928 – First realized as the Comprex, high pressure section of a threemegawatt locomotive gas turbine for British Rail. • First Mass-Produced Commercial Application – Comprex supercharger for diesel engines – Commercially from 1949 through today • NASA Wave Rotor Program • University Wave Rotor Programs – UF Wave Turbine Program – IUPUI Wave Combustor Program* – MSU Micro Wave Rotor Program* * Current Programs 2

Subscale Engine Exhaust Containment System Phase 2: Hydrogen Wave Heater Wave Rotor Applications Many Different Applications for Wave Rotors have been Researched Some made it into Production / Operation Others are still being Researched Some did not Wave Rotor Combustor Rig at Indiana University – Purdue University at Indianapolis (IUPUI) Comprex Super Charger for IC Engines CEC Wave Engine at the University of Florida NASA Topping Cycle for Gas Turbine Engines Micro Wave Rotor Experimental Set Up at Michigan State University CALSPAN Wave Superheater for High Enthalpy Test Gas 3

Subscale Engine Exhaust Containment System Phase 2: Hydrogen Wave Heater Why use a wave rotor for hightemperature gas generation? • Rotor Heating – • Pure Test Fluid – • Due to the periodic nature of the flow in the channels, there is an inherent self-cooling of the wave rotor, the maximum fluid temperature that can be delivered is several thousand degrees above the rotor material temperature, allowing for steady-state delivery of very high temperature gas using conventional materials Compression heating is used so no contaminants or vitiation is required to reach the very high temperatures Scalability – – Wave rotors, like most turbomachinery, are scalable to 100’s or even 1000’s of pounds per second of hot gas flow delivery Wave rotor loss mechanisms such as port leakage and heat loss have less effect at larger scales The wave rotor itself does no work on fluid, so shaft power does NOT scale with flow Compression heating results in very compact heater 4

Subscale Engine Exhaust Containment System Phase 2: Hydrogen Wave Heater Wave Rotor Basics Wave Rotors are a Class of Turbomachinery that Use Pressure Waves to Exchange Energy Onboard a Rotor • • Rotor – Rotating Bank of Shock Tubes (Channels) End Plates – Stationary with slots for ports. – Slots in end plates act as valves – When channel is exposed to slot (open) vs adjacent to a wall (closed) • • Flow Ports Slots End Plate Channels Rotor End Plate Ports Flow in Ports Provide Periodic Boundary Conditions that, when Timed Appropriately, Force Wave Patterns to Set Up Onboard the Rotor Speed Set by External Electric Motor 5

Subscale Engine Exhaust Containment System Phase 2: Hydrogen Wave Heater Wave Rotor Energy Exchange Mechanism • When operating on design, no shaft work is transferred to or from the working fluids • Energy is exchanged in the channels onboard the rotor using pressure shock waves • Temperature change in the fluid based on compression heating Pressure Ratio vs Temperature Ratio Across a Normal Shock Channels Normal Shock in a Duct 6

Subscale Engine Exhaust Containment System Phase 2: Hydrogen Wave Heater Results of a Conceptual Design Four-Port Pressure-Driven Wave Cycle with an OPR of 9. 9: 1 and TGTR of 2. 3 Simulation Results Non-Dimensional (b) Normalized Pressure (c) Normalized Temperature 1 Driven Gas 360⁰ Wave h-a P 2 = 1 T 2 = 1 Wave Cycle “Hot Zone” Driver Gas 2 Wave d-e Wave b-c Wave a-b Normalized Axial Distance Mass Interface Exhaust Gas Driven Gas P 1 = 9. 9 T 1 = 1 Shock Wave P 4 = 3. 1 T 4 = 0. 9 4 3 Test Gas 1 Driver Gas P 3 = 9. 5 T 3 = 2. 3 0⁰ U, rotor speed y, circ (a) Gas Streams x, axial Fluid Interface Pressure Wave Expansion Fan 7

Subscale Engine Exhaust Containment System Phase 2: Hydrogen Wave Heater Pre-Heater Design Concept: • Utilize Subscale Phase 1 Heater Design Fuel-Air Burner Concept Methane-Air Burner Fluid Temperatures Methane-Air Burner Solid Model 8

Subscale Engine Exhaust Containment System Phase 2: Hydrogen Wave Heater for Subscale ECS Testing North Cell 2, HWH Location E-3 Test Stand GH Line, 3” Sch. XXS E-1 Test Stand GH Bottles (2 -each) E-2 Test Stand E-Complex Control Rooms 9

Back-up Slides 10

Attribution: A large portion of information on several of the prior slides and several of the backup slides were produced by the following organization under a NASA SBIR Contract: 11

3” Sch. XXS Line Planview from Bottles to E-3 Test Cell 2 ~80’ 88’ Inlet to New Isolation Valve; Pressure Regulator, Check Valve, Pre-Heater, and HWH inlet are downstream North 175’-2” 88’-5” 6’ Elevation Change 125’ Tee to be reconnected and two isolation valves to be replaced 15’ 17’-9” 263’-9” Underground Section 287’ 275’ 8’ Elevation Changes, 2 places 3’ Elevation Change 12

North Test Cell 2 at E-3 Test Stand Subscale NTP Exhaust Capture System Components H 2 Heat Exchanger Steam Conde nser HWH Position • • Diffuser O 2 Injection Spray Chamber Debris Trap GO 2 Chiller Desiccant Filter GO 2 Conde nser LO 2 Exhau st Wa Storage ter St orage 13

North GH Bottles at E-2 Test Stand (750 ft 3 water volume each) 1. 5” Sch. 160 Line, from site HPGF 3” Sch. XXS Line Pressure Rating Break; 6000 -psig below to 3000 -psig above 14

The Shock Tube, Essentials Reference: Compressible Fluid Flow, 2 nd Ed. , by M. A. Saad, pp. 185 -192 High- and Low-pressure gas regions initially separated by a diaphragm Diaphragm ruptures and normal shock wave propagates through the low-pressure gas region Sharp pressure and temperature rise across the normal shock wave Additional temperature rise behind reflected shock wave 15

Wave Rotor Frames of Reference Rotor Frame of Reference • Rotates with the rotor • Essentially shock-tube analysis – Flow in channel is unsteady – Channel boundary conditions are time dependent Fluid Interface Pressure Wave Expansion Fan Stationary Frame of Reference • Unroll rotor circumferentially – Flow in ports is steady – Wave pattern is steady Blades 16

Wave Heater Performance Wave heater design For a given Operating Pressure Ratio (OPR): • Maximize the Test Gas Temperature Ratio (TGTR) • Minimize the Heater Mass Flow Ratio (HMFR) Wave Heater Performance Parameters Acronym Name TGTR Test Gas Temperature Ratio OPR Overall Pressure Ratio HMFR Heater Mass Flow Ratio Definition 1 Description TT 3 / TT 2 The TGTR is the temperature rise across the wave heater PT 1 / PT 2 The OPR is an indication of the amount of potential energy available to drive the compression heating The HMFR is the ratio of how much total gas must be delivered to the wave heater per unit mass flow of delivered test gas. Exhaust 4 Gas 2 Driven Gas 3 1 Driver Gas 17 Test Gas

Example Wave Heater Operating Point set by port 3 (target test conditions) • • • PT = 1120 psi TT = 5600 R MDOT = 1. 0 lbm/s Driven Gas OPR 10, No Mixing OPR TGTR HMFR 9. 80 2. 20 8. 25 Control Heater Wave Heater 2 To Vent (or Recovery) 4 q Hi Pressure Driver Gas Pre-Heater 1 q Test Cell 3 18