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Papers by jerry havens

Case 2 -Two canisters in room 8.

Journal of Hazardous Materials, 1987

An interactive computer model (DEGADIS) which uses a lumped parameter approach to simulate a wide... more An interactive computer model (DEGADIS) which uses a lumped parameter approach to simulate a wide variety of denser-than-air gas release scenarios, including instantaneous releases, time-varying releases, and continuous releases on a flat, obstacle-free surface is briefly described. The model accounts for negative buoyancy-induced and stably stratified shear flows and is consistent with the limiting passive dispersion characteristics of demonstrated air pollution models. Predicted maximum concentration as a function of distance is compared to the maximum reported concentration for field scale releases of liquefied natural gas (LNG) , liquefied petroleum gas (LPG as propane), and Freon-12/nitrogen mixtures from the Burro/Coyote, Maplin Sands, and Thorney Island Phase I trials, respectively. From these, the variability of the distance realized to a concentration level of 5, 2.5, and 1% for a given release is quantified based on the predicted distance. Comparisons of observed and model-predicted dispersion of nitrogen tetroxide from a large scale field test program (the U.S. Air Force Eagle series) are also presented. 1.1 Negatiue buoyancy-dominated dispersion phase Rapid release of a DTAG may result in an initial cloud having similar vertical and horizontal dimensions. The initial behavior of such "compact clouds" [ 1 ] is controlled by the negative buoyancy-driven flow. The gravity-driven flow results in large scale turbulent structures which cause the cloud to dilute

Process Safety and Environmental Protection, 2001

Journal of Hazardous Materials, 1985

Abstract Laboratory experimental instantaneous releases of right circular cylindrical volumes of ... more Abstract Laboratory experimental instantaneous releases of right circular cylindrical volumes of heavy gas mixtures (Freon-12/air) with initial volumes ranging from 0.034 m 3 to 0.135 m 3 and specific gravities ranging from 2.2 to 4.2 are described. Ground level peak gas concentrations are reported, and comparisons are made with corresponding 0.4 m elevation peak gas concentrations measured in Thorney Island Phase I Trials 7 through 16. An initial dilution phase in the Thorney trials immediately following release is observed which appears relatively unaffected by the ambient wind and which results in an order of magnitude dilution of the gas cloud. This initial phase of the Thorney Island trials, which prevails for lower wind speeds, is modeled accurately by the calm-air laboratory experiments at ∼ 1 : 50 scale. A mathematical model developed for incorporation in the U.S. Coast Guard Hazard Assessment Computer System (HACS) is described, and simulations of selected Thorney Island Phase I trials are compared with field measurements.

Journal of Hazardous Materials, 1982

A comparison is reported between experimental data obtained from spills of heavy gas or volatile ... more A comparison is reported between experimental data obtained from spills of heavy gas or volatile liquids and predictions of five different models of heavy vapor cloud dispersion. The models chosen for comparison and their sources are: MARIAH (Deygon-Ra, Inc.), ZEPHYR (Energy Resources Co., Inc.), HEGADAS-II (Shell), Eidsvik's "top hat" model (Norwegian Institute for Air Research), and the Germeles and Drake "top hat" model (Cabot Corp.). They are compared with the experimental LNG spills by Esso Research and Engineering Co. on water at Matagorda Bay, Texas (specifically Esso Runs 11, 16, 17) and the releases of heavy gas at Porton Down, Gt. Britain, sponsored by the Health and Safety Executive (specifically HSE Trials 6, 8, 20). It was found that the eddy diffusivity (K-theory) type of models, MARIAH and ZEPHYR, were best able to fit the HSE Porton Down data (for both near and far, high and low sensors). The HEGADAS-II model predictions best fit Esso Runs 11 and 17. However, HEGADAS-II cannot describe the calm wind cases, Esso Run 16 and HSE Trial 8. The Eidsvik model is recommended as one of the most advanced of the "top hat" class of models. It generally matches well the HSE Porton Down data for which it w&s calibrated. However, both HEGADAS-II and Eidsvik's model poorly fit sensor responses close to the source in the HSE trials; more distant sensors are matched better. The Germeles and Drake model seriously overpredicts air entrainment for HSE Trial 8, and overpredicts cloud dimensions for Esso Run 16. It reverts to the neutrally buoyant Gaussian form for four of the six experiments considered.

Phase Doppler Anemometry (PDA) measurements of velocity and droplet size distribution have recent... more Phase Doppler Anemometry (PDA) measurements of velocity and droplet size distribution have recently been reported for two-phase flashing jets. Two-phase flashing jets are predicted to occur when chemicals stored at elevated pressures and temperature are accidentally released to the atmosphere. The principle determinant of the initial dilution rate of a two-phase jet released to the atmosphere is its velocity after depressurization to atmospheric pressure. The maximum stable droplet size can be related to the initial velocity by a Weber number criteria. It has been shown that the initial velocity can be an important determinant of the flammable extent of a j release as well as the maximum possible rainout of liquid based on predicted droplet sizes. This paper summarizes present models for flashing single-component, two-phase flow through orifices. Model predictions are compared with available data including rainout data from flashing two-phase flow experiments designed to maximize th...

The SIGMET-N, ZEPHYR, MARIAH-II, and FEM3 computer models were evaluated for prediction of atmosp... more The SIGMET-N, ZEPHYR, MARIAH-II, and FEM3 computer models were evaluated for prediction of atmospheric dispersion of LNG vapor clouds. The SIGMET-N model is considered unsuitable for prediction of LNG vapor-cloud dispersion due to the impracticality of controlling numerical diffusion by grid fine-zoning and the use of a turbulent mixing submodel which does not scale properly. The ZEPHYR model is also considered unsuitable, primarily because of the use of a Lagrangian particle method for solving the gas mass balance equation which is not applicable to such strongly density-stratified flows. The numerical diffusion properties and the turbulent mixing submodels of MARIAH-II and FEM3 were evaluated by comparison of their predictions with analytical solutions, laboratory-scale gas-dispersion experiments comprising neutrally buoyant to strongly density-stratified two- and three-dimensional flows, and selected field experiments from the Thorney Island Heavy Gas Trials and the DOE Burro LNG...

The mathematical-modeling techniques used to predict atmospheric dispersion of heavier-than-air g... more The mathematical-modeling techniques used to predict atmospheric dispersion of heavier-than-air gases discussed in Volume 1 are briefly summarized; these techniques are incorporated in an interactive computer model DEGADIS. Details of DEGADIS implementation are briefly discussed. The necessary input information to simulate a heavier-than-air gas release with DEGADIS is summarized. Example simulations of a steady-state and transient release are included. A list of DEGADIS self-diagnostics with suggested actions are included. A listing of DEGADIS is included along with a partial list of program variables. Guidelines for installation of DEGADIS are presented.

A technique for measuring low velocities (0.2 1.4 m/s) in gas mixtures using hot-film anemometry ... more A technique for measuring low velocities (0.2 1.4 m/s) in gas mixtures using hot-film anemometry (with an independent concentration measurement) is described; the technique was applied to mixtures of air and carbon dioxide (0 to 100%) with hot film sensors (250°C overheat). For this system, the calibration curve for any CO 2 /air mixture could be determined to sufficient accuracy (within 5% of reading) by interpolation from the pure component calibration curves.

Heavy Gas and Risk Assessment — II

This work was supported by U.S. Coast Guard Contract DTCG23-80-C-20029 with the University of Ark... more This work was supported by U.S. Coast Guard Contract DTCG23-80-C-20029 with the University of Arkansas. The opinions or assertions contained herein are the private ones of the writers and are not to be construed as official or reflecting the views of the Commandant or the Coast Guard at large.

Process Safety and Environmental Protection

Bulletin of the Atomic Scientists

ABSTRACT Careful study of the consequences of spill fires can settle terminal-siting questions.

Bulletin of the Atomic Scientists

N SEPTEMBER 27, 2001, THE liquefied natural gas (LNG) tanker Matthew, operated by a Norwegian shi... more N SEPTEMBER 27, 2001, THE liquefied natural gas (LNG) tanker Matthew, operated by a Norwegian shipping company, was denied entry into Boston Harbor, where it had a scheduled delivery. "One of my functions," explained Coast Guard Port of Boston Captain Brian Salerno, "is to provide for safe and secure transportation of maritime traffic in Boston Harbor. Since September 11 the dynamics of that role have changed." But what are the connections between the dangers of shipping LNG and terrorism? There are only four LNG import terminals in the United States: Chesapeake Bay, Maryland; Lake Charles, Louisiana; Elba Island, Georgia; and Everett, Massachusetts. Tankers traveling to Everett, in Boston Harbor, pass near heavily populated areas. Along both inbound and outbound routes, LNG ships travel within several hundred yards of the Boston waterfront, past the end of the Logan International Airport runway from which two planes left for the World Trade Towers, and under a busy bridge. Even now, ships coming into Everett are subjected to greater scrutiny than before September 11. The LNG carrier Matthew passes under the bridge at Boston Harbor.

Process Safety and Environmental Protection

Case 2 -Two canisters in room 8.

Journal of Hazardous Materials, 1987

An interactive computer model (DEGADIS) which uses a lumped parameter approach to simulate a wide... more An interactive computer model (DEGADIS) which uses a lumped parameter approach to simulate a wide variety of denser-than-air gas release scenarios, including instantaneous releases, time-varying releases, and continuous releases on a flat, obstacle-free surface is briefly described. The model accounts for negative buoyancy-induced and stably stratified shear flows and is consistent with the limiting passive dispersion characteristics of demonstrated air pollution models. Predicted maximum concentration as a function of distance is compared to the maximum reported concentration for field scale releases of liquefied natural gas (LNG) , liquefied petroleum gas (LPG as propane), and Freon-12/nitrogen mixtures from the Burro/Coyote, Maplin Sands, and Thorney Island Phase I trials, respectively. From these, the variability of the distance realized to a concentration level of 5, 2.5, and 1% for a given release is quantified based on the predicted distance. Comparisons of observed and model-predicted dispersion of nitrogen tetroxide from a large scale field test program (the U.S. Air Force Eagle series) are also presented. 1.1 Negatiue buoyancy-dominated dispersion phase Rapid release of a DTAG may result in an initial cloud having similar vertical and horizontal dimensions. The initial behavior of such "compact clouds" [ 1 ] is controlled by the negative buoyancy-driven flow. The gravity-driven flow results in large scale turbulent structures which cause the cloud to dilute

Process Safety and Environmental Protection, 2001

Journal of Hazardous Materials, 1985

Abstract Laboratory experimental instantaneous releases of right circular cylindrical volumes of ... more Abstract Laboratory experimental instantaneous releases of right circular cylindrical volumes of heavy gas mixtures (Freon-12/air) with initial volumes ranging from 0.034 m 3 to 0.135 m 3 and specific gravities ranging from 2.2 to 4.2 are described. Ground level peak gas concentrations are reported, and comparisons are made with corresponding 0.4 m elevation peak gas concentrations measured in Thorney Island Phase I Trials 7 through 16. An initial dilution phase in the Thorney trials immediately following release is observed which appears relatively unaffected by the ambient wind and which results in an order of magnitude dilution of the gas cloud. This initial phase of the Thorney Island trials, which prevails for lower wind speeds, is modeled accurately by the calm-air laboratory experiments at ∼ 1 : 50 scale. A mathematical model developed for incorporation in the U.S. Coast Guard Hazard Assessment Computer System (HACS) is described, and simulations of selected Thorney Island Phase I trials are compared with field measurements.

Journal of Hazardous Materials, 1982

A comparison is reported between experimental data obtained from spills of heavy gas or volatile ... more A comparison is reported between experimental data obtained from spills of heavy gas or volatile liquids and predictions of five different models of heavy vapor cloud dispersion. The models chosen for comparison and their sources are: MARIAH (Deygon-Ra, Inc.), ZEPHYR (Energy Resources Co., Inc.), HEGADAS-II (Shell), Eidsvik's "top hat" model (Norwegian Institute for Air Research), and the Germeles and Drake "top hat" model (Cabot Corp.). They are compared with the experimental LNG spills by Esso Research and Engineering Co. on water at Matagorda Bay, Texas (specifically Esso Runs 11, 16, 17) and the releases of heavy gas at Porton Down, Gt. Britain, sponsored by the Health and Safety Executive (specifically HSE Trials 6, 8, 20). It was found that the eddy diffusivity (K-theory) type of models, MARIAH and ZEPHYR, were best able to fit the HSE Porton Down data (for both near and far, high and low sensors). The HEGADAS-II model predictions best fit Esso Runs 11 and 17. However, HEGADAS-II cannot describe the calm wind cases, Esso Run 16 and HSE Trial 8. The Eidsvik model is recommended as one of the most advanced of the "top hat" class of models. It generally matches well the HSE Porton Down data for which it w&s calibrated. However, both HEGADAS-II and Eidsvik's model poorly fit sensor responses close to the source in the HSE trials; more distant sensors are matched better. The Germeles and Drake model seriously overpredicts air entrainment for HSE Trial 8, and overpredicts cloud dimensions for Esso Run 16. It reverts to the neutrally buoyant Gaussian form for four of the six experiments considered.

Phase Doppler Anemometry (PDA) measurements of velocity and droplet size distribution have recent... more Phase Doppler Anemometry (PDA) measurements of velocity and droplet size distribution have recently been reported for two-phase flashing jets. Two-phase flashing jets are predicted to occur when chemicals stored at elevated pressures and temperature are accidentally released to the atmosphere. The principle determinant of the initial dilution rate of a two-phase jet released to the atmosphere is its velocity after depressurization to atmospheric pressure. The maximum stable droplet size can be related to the initial velocity by a Weber number criteria. It has been shown that the initial velocity can be an important determinant of the flammable extent of a j release as well as the maximum possible rainout of liquid based on predicted droplet sizes. This paper summarizes present models for flashing single-component, two-phase flow through orifices. Model predictions are compared with available data including rainout data from flashing two-phase flow experiments designed to maximize th...

The SIGMET-N, ZEPHYR, MARIAH-II, and FEM3 computer models were evaluated for prediction of atmosp... more The SIGMET-N, ZEPHYR, MARIAH-II, and FEM3 computer models were evaluated for prediction of atmospheric dispersion of LNG vapor clouds. The SIGMET-N model is considered unsuitable for prediction of LNG vapor-cloud dispersion due to the impracticality of controlling numerical diffusion by grid fine-zoning and the use of a turbulent mixing submodel which does not scale properly. The ZEPHYR model is also considered unsuitable, primarily because of the use of a Lagrangian particle method for solving the gas mass balance equation which is not applicable to such strongly density-stratified flows. The numerical diffusion properties and the turbulent mixing submodels of MARIAH-II and FEM3 were evaluated by comparison of their predictions with analytical solutions, laboratory-scale gas-dispersion experiments comprising neutrally buoyant to strongly density-stratified two- and three-dimensional flows, and selected field experiments from the Thorney Island Heavy Gas Trials and the DOE Burro LNG...

The mathematical-modeling techniques used to predict atmospheric dispersion of heavier-than-air g... more The mathematical-modeling techniques used to predict atmospheric dispersion of heavier-than-air gases discussed in Volume 1 are briefly summarized; these techniques are incorporated in an interactive computer model DEGADIS. Details of DEGADIS implementation are briefly discussed. The necessary input information to simulate a heavier-than-air gas release with DEGADIS is summarized. Example simulations of a steady-state and transient release are included. A list of DEGADIS self-diagnostics with suggested actions are included. A listing of DEGADIS is included along with a partial list of program variables. Guidelines for installation of DEGADIS are presented.

A technique for measuring low velocities (0.2 1.4 m/s) in gas mixtures using hot-film anemometry ... more A technique for measuring low velocities (0.2 1.4 m/s) in gas mixtures using hot-film anemometry (with an independent concentration measurement) is described; the technique was applied to mixtures of air and carbon dioxide (0 to 100%) with hot film sensors (250°C overheat). For this system, the calibration curve for any CO 2 /air mixture could be determined to sufficient accuracy (within 5% of reading) by interpolation from the pure component calibration curves.

Heavy Gas and Risk Assessment — II

This work was supported by U.S. Coast Guard Contract DTCG23-80-C-20029 with the University of Ark... more This work was supported by U.S. Coast Guard Contract DTCG23-80-C-20029 with the University of Arkansas. The opinions or assertions contained herein are the private ones of the writers and are not to be construed as official or reflecting the views of the Commandant or the Coast Guard at large.

Process Safety and Environmental Protection

Bulletin of the Atomic Scientists

ABSTRACT Careful study of the consequences of spill fires can settle terminal-siting questions.

Bulletin of the Atomic Scientists

N SEPTEMBER 27, 2001, THE liquefied natural gas (LNG) tanker Matthew, operated by a Norwegian shi... more N SEPTEMBER 27, 2001, THE liquefied natural gas (LNG) tanker Matthew, operated by a Norwegian shipping company, was denied entry into Boston Harbor, where it had a scheduled delivery. "One of my functions," explained Coast Guard Port of Boston Captain Brian Salerno, "is to provide for safe and secure transportation of maritime traffic in Boston Harbor. Since September 11 the dynamics of that role have changed." But what are the connections between the dangers of shipping LNG and terrorism? There are only four LNG import terminals in the United States: Chesapeake Bay, Maryland; Lake Charles, Louisiana; Elba Island, Georgia; and Everett, Massachusetts. Tankers traveling to Everett, in Boston Harbor, pass near heavily populated areas. Along both inbound and outbound routes, LNG ships travel within several hundred yards of the Boston waterfront, past the end of the Logan International Airport runway from which two planes left for the World Trade Towers, and under a busy bridge. Even now, ships coming into Everett are subjected to greater scrutiny than before September 11. The LNG carrier Matthew passes under the bridge at Boston Harbor.

Process Safety and Environmental Protection