Steadying the instability of a glowing discharge in a longitudinal air stream

Pollutant emission from a heat station supplied with agriculture biomass and wood pellet mixtureTests for combustion of hay and sunflower husk pellets mixed with wood pellets were performed in a horizontal-feed as well as under-feed (retort) wood pellet furnace installed in boilers with a nominal heat output of 15 and 20 kW, located in a heat station. During the combustion a slagging phenomenon was observed in the furnaces. In order to lower the temperature in the furnace, fuel feeding rate was reduced with unaltered air stream rate. The higher the proportion of wood pellets in the mixture the lower carbon monoxide concentration. The following results of carbon monoxide concentration (in mg/m3presented for 10% O2content in flue gas) for different furnaces and fuel mixtures (proportion in wt%) were obtained: horizontal-feed furnace supplied with hay/wood: 0/100 - 326; 30/70 - 157; 50/50 - 301; 100/0 - 3300; horizontal-feed furnace supplied with sunflower husk/wood: 50/50 - 1062; 67/33 - 1721; 100/0 - 3775; under-feed (retort) furnace supplied with hay/wood: 0/100 - 90; 15/85 - 157; 30/70 - 135; 50/50 - 5179; under-feed furnace supplied with sunflower husk/wood: 67/33 - 2498; 100/0 - 3128. Boiler heat output and heat efficiency was low: 7 to 13 kW and about 55%, respectively, for the boiler with horizontal-feed furnace and 9 to 14 kW and 64%, respectively, for the boiler with under-feed furnace.

Download Full-text

Estimates of oxides of nitrogen formed in an inlet air stream for high Mach number flight conditions

10.2514/6.1989-197 ◽

1989 ◽

Author(s):

L. CHIAPPETTA ◽

J. SANGIOVANNI

Keyword(s):

Mach Number ◽

Oxides Of Nitrogen ◽

High Mach Number ◽

Air Stream ◽

High Mach

Download Full-text

Failure Analysis Case Study of a 1.5 Meter Space Flex Harness

ISTFA 2017: Conference Proceedings from the 43rd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2017p0631 ◽

2017 ◽

Author(s):

Erick Kim ◽

Kamjou Mansour ◽

Gil Garteiz ◽

Javeck Verdugo ◽

Ryan Ross ◽

...

Keyword(s):

Failure Analysis ◽

Failure Modes ◽

Field Of View ◽

Area Of Interest ◽

Air Stream ◽

Novel Method ◽

Temperature Controlled ◽

Non Destructive ◽

Failure Site

Abstract This paper presents the failure analysis on a 1.5m flex harness for a space flight instrument that exhibited two failure modes: global isolation resistances between all adjacent traces measured tens of milliohm and lower resistance on the order of 1 kiloohm was observed on several pins. It shows a novel method using a temperature controlled air stream while monitoring isolation resistance to identify a general area of interest of a low isolation resistance failure. The paper explains how isolation resistance measurements were taken and details the steps taken in both destructive and non-destructive analyses. In theory, infrared hotspot could have been completed along the length of the flex harness to locate the failure site. However, with a field of view of approximately 5 x 5 cm, this technique would have been time prohibitive.

Download Full-text