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Combustion-Heated Scramjet Test Facility

NASA Langley Research Center
The Langley Combustion Heated Scramjet Test Facility is part of the NASA Langley Scramjet Test Complex. This facility offers the capability to test subscale propulsive flowpaths of hypersonic vehicles at conditions simulating flight Mach numbers from 3.5 to 6.0.
Facility Layout and Operation
Combustion-Heated Scramjet Test Facility Characteristics
The Langley Combustion Heated Scramjet Facility (CHSTF) has historically been used to test complete (inlet,combustor, and partial nozzle) subscale scramjet component integration models in flows with stagnation enthalpies duplicating that of flight at Mach numbers from 3.5 to 6.

Combustion Heated Scramjet Test Facility. As shown in the schematic,the CHSTF is located ina 16- by 16- by 52-ft test cell with forced air ventilation through the entire cell. This facility is adjacent to the DCSCTF and both facilities share the same gas and vacuum systems and portions of the data acquisition system.Test air is supplied from a high-pressure bottle field and is regulated to 550 psia (nominal) prior to entering the test cell. Both gaseous hydrogen and oxygen are supplied from tube trailers at a maximum pressure of 2400 psia and regulated to 720 psia prior to entering the test cell.Purge nitrogen is also supplied from a tube trailer at a maximum pressure of 2400 psia with the pressure regulated to 230 psia. Vacuum for altitude simulation is provided by a 70-ft diameter vacuum sphere and steam ejector system.

The CHSTF uses a hydrogen,air,and oxygen heater to obtain the flight stagnation enthalpy required for engine testing.The facility heater is shown in the schematic.

Oxygen is replenished in the heater to obtain a test gas with the oxygen mole fraction of air (0.2095).The facility may be operated with either a Mach 3.5 or 4.7 nozzle. Both nozzles have square cross sections and are contoured to exit dimensions of 13.26 by 13.26 in. The nozzle flow exhausts as a free jet into the test section,which is 42-in high by 30-in wide by 96-in long. The free jet passes through and around the engine model and then into a catch cone diffuser.The flow is typically exhausted into a 70-ft diameter vacuum sphere.

Either gaseous hydrogen or gaseous ethylene (both at ambient temperature) may be used as the primary fuel in the scramjet engines tested in the CHSTF. A 20-percent silane, 80-percent hydrogen mixture (by volume) is available for use in the scramjet model as an ignitor/pilot gas to aid in the combustion of the primary fuel.
Simulated Flight Mach number 3.5 to 6
Nozzle Exit Mach number 3.5 and 4.7
Simulated Flight Dynamic Pressure, per square foot* 250 to 3500
Nozzle Exit Area, inches 13.26 by 13.26
Test gas hydrogen-air combustion products with oxygen replenishment
Heater Total pressure, psia 50 to 500
Heater Total temperature, ?R 1300 - 3000
*Depending on Mach Number


Combustion-Heated Scramjet Test Facility heater and plenum chamber.
Combustion-Heated Scramjet Test Facility heater and plenum chamber.
Combustion Heated Scramjet Test Facility.
Combustion Heated Scramjet Test Facility.
Data Acquisition and Processing
The data acquisition system consists of a commercially available software package (AutoNet) running on a Pentium processor. The DAS incorporates a NEFF 300 signal conditioner and a NEFF 600 amplifier/multiplexer capable of supporting 128 channels. In addition, up to 512 static pressure measurements can be recorded using a PSI 8400 ESP system and sixteen 32-port modules. Engine thrust and drag are measured with a load cell.Test data are typically transferred to a UNIX workstation for data analysis. Limited optical access is available for flow visualization. A secure operating mode is provided for classified projects.

Facilities Available to Users
A model preparation room is available for assembly and check out of unclassified test articles.

Safety and Design Criteria
Langley?s LHB 1710.15 Wind Tunnel Model System Criteria is the guideline for model design and fabrication. Model installation and any exceptions to this document must have the approval of the 0.3-M TCT Safety Head on a case-by-case basis to assure personnel and tunnel hardware are not exposed to risk. 		Test Capabilities
The facility normally operates at heater stagnation pressures between 50 and 500 psia and at stagnation temperatures between 1300 and 3000 �R. Test gas mass flow rates range from 15 to 60 lbm/s. The range of operation is shown by the Mach number and altitude simulation envelope.

Mach number and altitude simulation envelope.

The left vertical boundary of the envelope is the nozzle exit Mach number of 3.5 and the right vertical boundary reflects the maximum heater operating temperature of 3000 �R. The upper inclined boundary represents the minimum operating pressure of 50 psia,up to an altitude where a simulated flight dynamic pressure of 250 psf is imposed as a limit. The lower inclined boundary reflects the maximum mass flow rate to the heater at the Mach number of 3.5 limit and the maximum heater operating pressure at the Mach number of 6 limit. The standard operating conditions of the CHSTF are shown by the symbols on the figure and are tabulated below.

Standard Test Conditions

Calculated test gas compositions for the standard operating conditions are given in the table for species mole fractions of 0.0001 or greater.

Test Gas Mole Fractions

The primary contaminant in the test gas is water vapor,which varies from 0.085 mole fraction at Mach number of 4 to 0.179 at Mach 5.5.

The normal operational schedule of the CHSTF is 2 to 3 days per week. Test runs average 20 to 30 seconds duration with multiple runs (5+) per day.
Model Supports
Engine models are typically attached to two overhead support beams located inside the facility test cabin. The support beams can be adjusted to position the engine at various locations within the flow at the nozzle exit.
Type of Testing
 Test Request Procedures
Hydrocarbon-fueled scramjet engine model
Hydrocarbon-fueled scramjet engine model.		 The CHSTF has been in operation since 1978.Extensive tests,a total of 1874 to date,have been conducted to investigate the operability and performance of various component integration engines. Scramjet engines tested in this facility include the NASA 3-Strut, NASA Parametric, NASA Step-Strut, NASP Government Baseline, Rocketdyne A2, Pratt and Whitney C,JHU/APL B1,and most recently,the Rocketdyne Hydrocarbon-Fueled Scramjet.

The purpose of the Rocketdyne Hydrocarbon-Fueled Scramjet test series was to establish a database for a gaseous ethylene-fueled,fixed-geometry, complete scramjet engine module. The tests were conducted at simulated Mach 4 flight conditions with the ethylene acting as a surrogate for cracked jet fuel. A of the engine mounted in the test cabin is shown below.Portions of the facility nozzle extension and catch cone diffuser have been removed for engine visibility. 		The first step of the test process is to submit a test request form. The form can be filled out electronically or printed for mailing at the NASA Langley aero Compass website. A posttest questionnaire is also available at this site. Our customers are encouraged to provide feedback to the facility for our continuous improvement process.
Document Version 1.0
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The use of trademarks or names of manufacturers in this report is for accurate reporting and does not constitute an official endorsement, either expressed or implied, of such products or manufacturers by the National Aeronautics and Space Administration.
For more information contact:
The Combustion-Heated Scramjet Test Facility Manager -- NASA Langley Research Center -- Hampton, Virginia 23681-2199
phone: 757 � 864 � 1371 | fax: 757 � 864 � 6243 | e-mail: wte+fm_chstf@larc.nasa.gov
NASA Official Responsible For Content:
Pete Jacobs		 Page Curator: CONITS Development Team Date Last Updated:11/17/2005