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Seaford, Mark

Publications and source records attributed to Seaford, Mark.

Space Launch System Base Heating Test: Environments and Base Flow Physics

NASA MSFC and CUBRC designed and developed a 2% scale SLS propulsive wind tunnel test program to investigate base flow effects during flight from lift-off to MECO. This type of test program has not been conducted in 40+ years during the NASA Shuttle Program. Dufrene et al paper described the operation, instrumentation type and layout, facility and propulsion performance, test matrix and conditions and some raw results. This paper will focus on the SLS base flow physics and the generation and results of the design environments being used to design the thermal protection system.

Mehta, Manish

Space Launch System Base Heating Test: Experimental Operations & Results

NASA's Space Launch System (SLS) uses four clustered liquid rocket engines along with two solid rocket boosters. The interaction between all six rocket exhaust plumes will produce a complex and severe thermal environment in the base of the vehicle. This work focuses on a recent 2% scale, hot-fire SLS base heating test. These base heating tests are short-duration tests executed with chamber pressures near the full-scale values with gaseous hydrogen/oxygen engines and RSRMV analogous solid propellant motors. The LENS II shock tunnel/Ludwieg tube tunnel was used at or near flight duplicated conditions up to Mach 5. Model development was based on the Space Shuttle base heating tests with several improvements including doubling of the maximum chamber pressures and duplication of freestream conditions. Test methodology and conditions are presented, and base heating results from 76 runs are reported in non-dimensional form. Regions of high heating are identified and comparisons of various configuration and conditions are highlighted. Base pressure and radiometer results are also reported.

Dufrene, Aaron

Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development and Performance Analysis

The Space Launch System (SLS) base heating test is broken down into two test programs: (1) Pathfinder and (2) Main Test. The Pathfinder Test Program focuses on the design, development, hot-fire test and performance analyses of the 2% sub-scale SLS core-stage and booster element propulsion systems. The core-stage propulsion system is composed of four gaseous oxygen/hydrogen RS-25D model engines and the booster element is composed of two aluminum-based model solid rocket motors (SRMs). The first section of the paper discusses the motivation and test facility specifications for the test program. The second section briefly investigates the internal flow path of the design. The third section briefly shows the performance of the model RS-25D engines and SRMs for the conducted short duration hot-fire tests. Good agreement is observed based on design prediction analysis and test data. This program is a challenging research and development effort that has not been attempted in 40+ years for a NASA vehicle.

Mehta, Manish

Space Launch System Base Heating Test: Sub-Scale Rocket Engine/Motor Design, Development & Performance Analysis

ATA-002 Technical Team has successfully designed, developed, tested and assessed the SLS Pathfinder propulsion systems for the Main Base Heating Test Program. Major Outcomes of the Pathfinder Test Program: Reach 90% of full-scale chamber pressure Achieved all engine/motor design parameter requirements Reach steady plume flow behavior in less than 35 msec Steady chamber pressure for 60 to 100 msec during engine/motor operation Similar model engine/motor performance to full-scale SLS system Mitigated nozzle throat and combustor thermal erosion Test data shows good agreement with numerical prediction codes Next phase of the ATA-002 Test Program Design & development of the SLS OML for the Main Base Heating Test Tweak BSRM design to optimize performance Tweak CS-REM design to increase robustness MSFC Aerosciences and CUBRC have the capability to develop sub-scale propulsion systems to meet desired performance requirements for short-duration testing.

Mehta, Manish

Engineering methodology to estimate the aerodynamic heating to the base of the Aeroassist Flight Experiment vehicle

An engineering methodology has been developed to predict the convective heating and pressure environments to the base surfaces of the Aeroassist Flight Experiment (AFE) vehicle during its earth aeropass. Data obtained from prior flight vehicles, wind tunnel tests, CFD analysis of AFE, and simple one-dimensional isentropic flow expansion relationships along with standard aeroheating methods were employed. With the exception of one corner, the AFE base surfaces are immersed in separated flow and are, therefore, exposed to heating and pressure that are small compared to the front face of the aerobrake.

Sambamurthi, Jay