Showing papers on "Overpressure published in 1976"

Combustion of pulverized coal

Abstract: This invention relates to a process and apparatus for the combustion of pulverized coal, wherein the pulverized coal is introduced into a conditioned atmosphere having an overpressure, the overpressure being used to accelerate a flame jet, and wherein the flame jet is injected into an atmosphere having a temperature below the ash melting temperature of the fired coal.

Statistical model of sonic boom structural damage

Abstract: The probabilities of structural damage from sonic booms were estimated for various susceptible structural elements using a statistical modeling technique. The breakage probabilities were found to vary widely with the specific material configuration, but to consistently increase with increasing nominal overpressures. The ranges of breakage probabilities at a nominal overpressure of 1 psf for typical configurations of susceptible materials were as follows: windows--.000004 to .00000003, plaster--.0003 to .0000005, bric-a-brac--.000001 to .00000001, brick walls--.0000006 to .000000001. The results of the modeling tend to agree well with sonic boom claims experience.

Ballistic range experiments on superbooms generated by refraction

Abstract: The enhanced sonic boom or supersonic boom generated as a result of atmospheric refraction in threshold Mach number flights was recreated in a ballistic range by firing projectiles at low supersonic speeds into a stratified medium obtained by slowly injecting carbon dioxide into air. The range was equipped with a fast-response dynamic pressure transducer and schlieren photographic equipment, and the sound speed variation with height was controlled by regulating the flow rate of the CO2. The schlieren observations of the resulting flow field indicate that the generated shocks are reflected near the sonic cutoff altitude where local sound speed equals body speed, provided such an altitude exists. Maximum shock strength occurs very nearly at the point where the incident and reflected shocks join, indicating that the presence of the reflected shock may have an appreciable effect on the magnitude of the focus factor. The largest focus factor detected was 1.7 and leads to an estimate that the constant in the Guiraud-Thery scaling law should have a value of 1.30.

Overpressure protection for insulant filled machines - has cover liftable by excessive pressure after which cover is replaced and sealed

Abstract: The device is for electric machines or apparatus filled with insulating liquid or gas, esp. for transformers, tap changers and load selectors. When existing overpressure exceeds a specified limit, it is released by lifting the cover, and the process is signalled by an electric switching device, or the plant is switched off. A large area cover (4) has a number of concentrically arranged pins (3) and is pressed to the liquid or gas filled tank by springs (6) on pins (3). It is sealed by a seal (7) and is lifted when pressure exceeds a limit. When pressure is reduced to normal, springs (6) automatically reclose the cover (4) and seal it.

Ballistic range experiments on the superboom generated at increasing flight Mach numbers

Abstract: Ballistic range experiments for the study of the propagation of converging shocks are described and the similarity between the observed phenomenon and that expected for superbooms created by accelerating supersonic aircraft is discussed For weak shocks (shock Mach numbers of about 103), a structure resembling that of a folded shock predicted by geometrical acoustics theory is observed while for stronger shocks, a concave front with enhanced overpressure is recorded Other results are in general accord with the basic concepts of shock propagation and in conjunction with some theoretical scaling laws indicate that the peak magnification of sonic booms due to aircraft flight acceleration in the real atmosphere should be in the range of 6 to 13Subject Classification: [43]2520, [43]2530; [43]2855; [43]5055

Project DIPOLE WEST - Multiburst Environment (Non-Simultaneous Detonations)

Abstract: : DIPOLE WEST (Non-Simultaneous Detonations) is a series of five high explosive experiments conducted by USA Ballistic research Laboratories at the Defence Research Establishment, Suffield, in Alberta, Canada, during the fall of 1974 and spring of 1975 One of the experiments involved detonation of a single 216-pound pentolite charge; the remaining experiments consisted of two 216-pound pentolite charges for each event The charges were detonated non-simultaneously, with times between detonations of 0, 3, 5, and 10 milliseconds Purpose of the series was to obtain information on the phenomenology of strong shock on shock, shock on fireball, and fireball flow interactions from the detonation of multiple high explosive charges Density, particle velocity, stagnation pressure, and overpressure were measured at and near the ground surface as well as at and near the plane midway between charges Measurment techniques included pressure tranducers and high speed photography A Mach stem seen between the charges for shots with 0 and 3 millisecond separation times was not observed on the 5 and 10 millisecond shots Comparisons made with the AFWL HULL hydrodynamic air blast code show good correlation

Super liquid pressure pump

Abstract: PURPOSE:To obtain variable fluid quantity under constant pressure corresponding to variable flow quantity load and to prevent overpressure in a drain pipe by establishment of pressure regulating cylinder in a drain pipe.

Hydrodynamic containment for underground nuclear power plants

Abstract: The containment capability of mined subterranean caverns for siting nuclear power plants depends on the flow of groundwater through porous media surrounding the cavern. For a simple cylindrical containment cavern, design correlations were developed relating depth of burial to cavern overpressure. Considering 50 psig as the maximum containment overpressure following a postulated loss-of-coolant accident (LOCA), the minimum depth of burial below the groundwater table for a cavern of 50-ft radius is approximately 200 ft. These conditions assure no cavern water flow through the rock to the atmosphere and no cavern contaminant seepage into the groundwater following a postulated LOCA. (auth)

Blast Loading on Model Dummies in Two-Room Shelters

Abstract: : Experimental results obtained from the blast loading of model dummies inside scaled two-room shelters are given for 20 and 49% open front walls. The translational velocities of the model dummies are given as a function of shelter configuration and the experimental overpressure levels of 3 - 10 psi. The results obtained are scaled up to give predictions for full size shelters.