\u3ci\u3eLibellula Flavida\u3c/i\u3e (Odonata: Libellulidae), a Dragonfly New to Ohio

Libellula flavida, a widespread but uncommon dragonfly of southeastern and south central North America, is now recorded from Ohio. A breeding population was discovered in an acidic fen on the site of a sandstone quarry in southern Ohio

Heat pipes to reduce engine exhaust emissions

A fuel combustor is presented that consists of an elongated casing with an air inlet conduit portion at one end, and having an opposite exit end. An elongated heat pipe is mounted longitudinally in the casing and is offset from and extends alongside the combustion space. The heat pipe is in heat transmitting relationship with the air intake conduit for heating incoming air. A guide conduit structure is provided for conveying the heated air from the intake conduit into the combustion space. A fuel discharge nozzle is provided to inject fuel into the combustion space. A fuel conduit from a fuel supply source has a portion engaged in heat transfer relationship of the heat pipe for preheating the fuel. The downstream end of the heat pipe is in heat transfer relationship with the casing and is located adjacent to the downstream end of the combustion space. The offset position of the heat pipe relative to the combustion space minimizes the quenching effect of the heat pipe on the gaseous products of combustion, as well as reducing coking of the fuel on the heat pipe, thereby improving the efficiency of the combustor

Combustion overview

The objective of this effort is to develop improved analytical models of the internal combustor flow field and liner heat transfer as a means to shorten combustor development time and increase turbine engine hot section life. A four-element approach was selected to meet this objective. First, existing models were utilized to determine their deficiencies. Supporting research was then commenced to improve the exisiting models. While the research effort is in progress, the models are being refined to improve numerics and numerical diffusion. And lastly, the research results and improved numerics will be integrated into existing models

Exhaust emissions of a double annular combustor: Parametric study

A full scale double-annular ram-induction combustor designed for Mach 3.0 cruise operation was tested. Emissions of oxides of nitrogen, carbon monoxide, unburned hydrocarbons, and smoke were measured over a range of combustor operating variables including reference velocity, inlet air temperature and pressure, and exit average temperature. ASTM Jet-A fuel was used for these tests. An equation is provided relating oxides of nitrogen emissions as a function of the combustor, operating variables. A small effect of radial fuel staging on reducing exhaust emissions (which were originally quite low) is demonstrated

Modifications that improve performance of a double annular combustor at simulated engine idle conditions

Techniques were evaluated to determine if simple combustor modifications could be used to reduce the engine ground idle emissions of a double annular combustor designed for Mach 3.0 cruise operation. These techniques were radial fuel staging, the use of radial-inflow rather than axial-flow air swirlers, and the optimization of fuel-nozzle spray angle and differential pressure. Radial fuel staging and the use of radial-inflow air swirlers significantly improved performance at two ground idle test conditions simulating both low- and high-compression ratio engines

Ground idle performance improvement of a double-annular combustor by using simulated variable combustor geometry

A test program was undertaken to determine if variable combustor geometry could be used to reduce exhaust emissions of a low-pressure-ratio jet engine operating at ground idle conditions. Three techniques for varying combustor geometry were simulated. Other techniques evaluated were radial fuel staging and the use of preheated fuel. When simulated variable combustor geometry was employed with radial fuel staging, combustion efficiency at a fuel-air ratio of 0.01 was increased from 77 to 95 percent, and exhaust emissions of unburned hydrocarbons and carbon monoxide were significantly reduced

Techniques for enhancing durability and equivalence ratio control in a rich-lean, three-stage ground power gas turbine combustor

Rig tests of a can-type combustor were performed to demonstrate two advanced ground power engine combustor concepts: steam cooled rich-burn combustor primary zones for enhanced durability; and variable combustor geometry for three stage combustion equivalence ratio control. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This offers the potential of both long life and reduced use of strategic materials for liner fabrication. Three degrees of variable geometry were successfully implemented to control airflow distribution within the combustor. One was a variable blade angle axial flow air swirler to control primary airflow while the other two consisted of rotating bands to control secondary and tertiary or dilution air flow

Component testing of a ground based gas turbine steam cooled rich-burn primary zone combustor for emissions control of nitrogeneous fuels

This effort summarizes the work performed on a steam cooled, rich-burn primary zone, variable geometry combustor designed for combustion of nitrogeneous fuels such as heavy oils or synthetic crude oils. The steam cooling was employed to determine its feasibility and assess its usefulness as part of a ground based gas turbine bottoming cycle. Variable combustor geometry was employed to demonstrate its ability to control primary and secondary zone equivalence ratios and overall pressure drop. Both concepts proved to be highly successful in achieving their desired objectives. The steam cooling reduced peak liner temperatures to less than 800 K. This low temperature offers the potential of both long life and reduced use of strategic materials for liner fabrication. These degrees of variable geometry were successfully employed to control air flow distribution within the combustor. A variable blade angle axial flow air swirler was used to control primary zone air flow, while the secondary and tertiary zone air flows were controlled by rotating bands which regulated air flow to the secondary zone quench holes and the dilutions holes respectively

Investigation of potential anti-radiation and anti-neoplastic compounds related to plant growth regulators second quarterly progress report, 1 oct. 1964 - 1 jan. 1965

Antiradiation and antineoplastic compounds related to plant growth regulators - cytotoxic effects and radiation protectio