Significance and Use

American National Standards Institute Inc.

3.1 The purpose of this practice is to measure the total or stagnation gas enthalpy of a plasma-arc gas stream in which nonreactive gases are heated by passage through an electrical discharge device during calibration tests of the system.

3.2 The plasma arc represents one heat source for determining the performance of high temperature materials under simulated hyperthermal conditions. As such the total or stagnation enthalpy is one of the important parameters for correlating the behavior of ablation materials.

3.3 The most direct method for obtaining a measure of total enthalpy, and one which can be performed simultaneously with each material test, if desired, is to perform an energy balance on the arc chamber. In addition, in making the energy balance, accurate measurements are needed since the efficiencies of some plasma generators are low (as low as 15 to 20 % or less in which case the enthalpy depends upon the difference of two quantities of nearly equal magnitude). Therefore, the accuracy of the measurements of the primary variables must be high, all energy losses must be correctly taken into account, and steady-state conditions must exist both in plasma performance and fluid flow.

3.4 In particular it is noted that total enthalpy as determined by the energy balance technique is most useful if the plasma generator design minimizes coring effects. If nonuniformity exists the enthalpy determined by energy balance gives only the average for the entire plasma stream, whereas the local enthalpy experienced by a model in the core of the stream may be much higher. More precise methods are needed to measure local variations in total enthalpy.

Scope

1.1 This practice covers the measurement of total gas enthalpy of an electric-arc-heated gas stream by means of an overall system energy balance. This is sometimes referred to as a bulk enthalpy and represents an average energy content of the test stream which may differ from local values in the test stream.

1.2 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.

1.3 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

Go to ASTM E341 at ASTM.org

Add your thoughts about the standard.

1375 - Demolition Materials (549) 1377 - Cartridge and Propellant Actuated Devices and Components (524) 4720 - Hose and Flexible Tubing (552) 4730 - Hose, Pipe, Tube, Lubrication, and Railing Fittings (1823) 5120 - Hand Tools, Nonedged, Nonpowered (1124) 5305 - Screws (781) 5306 - Bolts (996) 5310 - Nuts and Washers (864) 5330 - Packing and Gasket Materials (583) 5340 - Hardware, Commercial (953) 5905 - Resistor (753) 5910 - Capacitors (783) 5930 - Switches (1012) 5935 - Connectors, Electrical (4357) 5940 - Lugs, Terminals, and Terminal Strips (564) 5945 - Relays and Solenoids (733) 5950 - Coils and Transformers (856) 5960 - Electron Tubes and Associated Hardware (1630) 5961 - Semiconductor Devices and Associated Hardware (707) 6145 - Wire and Cable, Electrical (1629) 6240 - Electric Lamps (662) 6505 - Drugs and Biologicals (1343) 6515 - Medical and Surgical Instruments, Equipment, and Supplies (1907) 6520 - Dental Instruments, Equipment, and Supplies (790) 6530 - Hospital Furniture, Equipment, Utensils, and Supplies (745) 6610 - Flight Instruments (540) 6625 - Electrical and Electronic Properties Measuring and Testing Instruments (1241) 6640 - Laboratory Equipment and Supplies (1187) 6810 - Chemicals (1114) 8010 - Paints, Dopes, Varnishes, and Related Products (2046) 8030 - Preservative and Sealing Compounds (554) 8140 - Ammunition and Nuclear Ordnance Boxes, Packages and Special Containers (797) 8305 - Textile Fabrics (910) 8415 - Clothing, Special Purpose (660) 8455 - Badges and Insignia (3093) 8915 - Fruits and Vegetables (531) 9330 - Plastics Fabricated Materials (759) FACR (1647) ISDA (1776) ISDD (786) ISDF (1827) ISDN (581) MISC (1045) PACK (539) SESS (581)
Aerospace Material (225) Aircraft Air Conditioning, Heating, and Pressurizing Equipment (334) Aircraft Hydraulic, Vacuum, and De-icing System Components (263) Ammunition, 75mm through 125mm (192) Ammunition, over 30mm up to 75mm (208) Ammunition, through 30mm (349) Analytical Chemistry (180) Bombs (192) Building (414) Bulk Explosives (261) Cartridge and Propellant Actuated Devices and Components (524) Consumer Product Evaluation (267) Copper (192) Demolition Materials (549) Electrical and Magnetic Conductor (162) Electronics (153) Environmental Toxicology (187) Fire Control Computing Sights and Devices (338) Fire Control Radar Equipment, except Airborne (197) Fuzes and Primers (454) Geotechnical Engineering (217) GUN (640) Land Mines (276) Medical Device and Implant (427) Military Chemical Agents (156) Miscellaneous Aircraft Accessories and Components (231) Miscellaneous Fire Control Equipment (216) Nondestructive Testing (246) Nonferrous Metal and Nonferrous Alloy (367) Nuclear Technology (274) Optical Sighting and Ranging Equipment (451) Paint and Related Coating (456) Parachutes; Aerial Pick Up, Delivery, Recovery Systems; and Cargo Tie Down Equipment (324) Petroleum (378) Plastic Pipe (248) Pyrotechnics (175) Road and Paving (177) Rockets, Rocket Ammunition and Rocket Components (368) Rubber (166) Security System Pedestrian and Walkway Safety (157) Specialized Test and Handling Equipment, Nuclear Ordnance (150) Sports and Recreation (316) Steel (908) Torpedos and Components, Inert (258) (621)