Flame spread along a fuel rod in the absence of gravity
An analysis is carried out of the steady spread of a flame with infinitely fast kinetics over a thermally thin solid rod in the absence of gravity. Due to the radial convergence on the solid surface of the heat flux heating and vaporizing the fuel, the spread rate is found to be higher than for a flame spreading over a slab, and the region of the gas around the flame which is affected by molecular transport is large compared with the radius of the rod. The effects of radiation, of a buoyancy force opposing flame propagation and of axial heat conduction in the solid are discussed briefly
Flame Spread Measurements on Single Ponderosa Pine Needles: Effect of Sample Orientation and Concurrent External Flow
Abstract Measurement of the flame spread rate on single ponderosa pine needles as a function of angle of inclination and concurrent external flow speed arc reported. The ability to fit the orientation results with a single curve is of particular interest. Consideration of the results of previous experimenters concurs with this observation. Temperature measurements, visible observations and order of magnitude estimates are used to discuss the physical mechanisms for increasing flame spread rate with increasing angle from the downwards vertical, or with concurrent external flow speed. Volume expansion, species diffusion, finite rate gas phase kinetics, and buoyant convection are all thought to play a role
Water Quality Aspects of Irrigation and Drainage: Past History and Future Challenges for Civil Engineers
This paper presents a brief history of irrigation and drainage related to ASCE activities on its Jubilee. This paper discusses legislation and policies that affect irrigation and drainage practices, water quality constituents of increasing concern in irrigation and drainage practices, and presents a prognosis on the future of declining freshwater resources available for irrigated agriculture and growing water quality problems in irrigation and drainage. Civil engineers in ASCE’s Irrigation and Drainage Division have compiled an 80-year history of highly meritorious service and accomplishments. In the next millennium, civil engineers will face a formidable challenge in managing and protecting the precious freshwater resources in the U.S.