The Pressure Peaking Phenomenon for Ignited Under-Expanded Hydrogen Jets in the Storage Enclosure: Experiments and Simulations for Release Rates of up to 11.5 g/s

This work focuses on the experimental and numerical investigation of maximum overpressure and pressure dynamics during ignited hydrogen releases in a storage enclosure, e.g., in marine vessel or rail carriage, with limited vent size area, i.e., the pressure peaking phenomenon (PPP) revealed theoretically at Ulster University in 2010. The CFD model previously validated against small scale experiments in a 1 m3 enclosure is employed here to simulate real-scale tests performed by the University of South-Eastern Norway (USN) in a chamber with a volume of 15 m3. The numerical study compares two approaches on how to model the ignited hydrogen release conditions for under-expanded jets: (1) notional nozzle concept model with inflow boundary condition, and (2) volumetric source model in the governing conservation equations. For the test with storage pressure of 11.78 MPa, both approaches reproduce the experimental pressure dynamics and the pressure peak with a maximum 3% deviation. However, the volumetric source approach reduces significantly the computational time by approximately 3 times (CFL = 0.75). The sensitivity analysis is performed to study the effect of CFL number, the size of the volumetric source and number of iterations per time step. An approach based on the use of a larger size volumetric source and uniform coarser grid with a mesh size of a vent of square size is demonstrated to reduce the duration of simulations by a factor of 7.5 compared to the approach with inflow boundary at the notional nozzle exit. The volumetric source model demonstrates good engineering accuracy in predicting experimental pressure peaks with deviation from −14% to +11% for various release and ventilation scenarios as well as different volumetric source sizes. After validation against experiments, the CFD model is employed to investigate the effect of cryogenic temperature in the storage on the overpressure dynamics in the enclosure. For a storage pressure equal to 11.78 MPa, it is found that a decrease of storage temperature from 277 K to 100 K causes a twice larger pressure peak in the enclosure due to the pressure peaking phenomenon

European hydrogen train the trainer framework for responders: Outcomes of the HyResponder project

HyResponder is a European Hydrogen Train the Trainer programme for responders. This paper describes the key outputs of the project and the steps taken to develop and implement a long-term sustainable train the trainer programme in hydrogen safety for responders across Europe and beyond. This FCH2 JU (now Clean Hydrogen Joint Undertaking) funded project has built on the successful outcomes of the previous HyResponse project. HyResponder has developed further and updated educational, operational, and virtual reality training for trainers of responders to reflect the state-of-the-art in hydrogen safety, including liquid hydrogen, and expand the programme across Europe and specifically within the 10 countries represented directly within the project consortium: Austria, Belgium, the Czech Republic, France, Germany, Italy, Norway, Spain, Switzerland, and the United Kingdom. For the first time, four levels of educational materials from fire fighter through to specialist have been developed. The digital training resources are available on the e-Platform (https://hyresponder.eu/e-platform/). The revised European Emergency Response Guide is now available to all stakeholders. The resources are intended to be used to support national training programs. They are available in 8 languages: Czech, Dutch, English, French, German, Italian, Norwegian and Spanish. Through the HyResponder activities, trainers from across Europe have undertaken joint actions which are in turn being used to inform the delivery of regional and national training both within and beyond the project. The established pan-European network of trainers is shaping the future in the important for inherently safer deployment of hydrogen systems and infrastructure across Europe and enhancing the reach and impact of the programme

Biosurfactants: Promising Molecules for Petroleum Biotechnology Advances

The growing global demand for sustainable technologies that improves the efficiency of petrochemical processes in the oil industry has driven advances in petroleum biotechnology in recent years. Petroleum industry uses substantial amounts of petrochemical-based synthetic surfactants in its activities as mobilizing agents to increase the availability or recovery of hydrocarbons as well as many other applications related to extraction, treatment, cleaning and transportation. However, biosurfactants have several potential applications for use across the oil processing chain and in the formulations of petrochemical products such as emulsifying/demulsifying agents, anticorrosive, biocides for sulphate-reducing bacteria, fuel formulation, extraction of bitumen from tar sands and many other innovative applications. Due to their versatility and proven efficiency, biosurfactants are often presented as valuable versatile tools that can transform and modernise petroleum biotechnology in an attempt to provide a true picture of state of the art and directions or use in the oil industry. We believe that biosurfactants are going to have a significant role in many future applications in the oil industries and in this review therefore, we highlight recent important relevant applications, patents disclosures and potential future applications for biosurfactants in petroleum and related industries

Developing a welfare-friendly training method for sport horses: behavior, pressure algometry and biomechanical measurements

Det er blitt analysert sammenhengen mellom atferdsmessige, fysiske og biomekaniske effekter for en systematisk ridemetode som tar sikte på å løsgjøre og bygge opp kjernemuskulaturen samtidig som den har en stressreduserende effekt. Målet var å se på atferdsmessige forandringer under denne ridningen og deres relasjon til hode- og nakkeposisjon, smertesensitivitet og muskeltonus, før og etter ridning, samt bevegelsesmønsteret til hestene under ridningen. Hypotesen foreslår at en dypere hode- og nakkeposisjon medfører økte positive atferdssignaler samtidig som det predikeres at hestene vil ha en nedgang i smertesensitivitet og en forandring i muskeltonus gitt ut fra hesten utgangspunkt (hypertonisk/spastisk). Hestene (n = 8) ble utstyrt med analyseverktøy fra Qualisys og X-IO for å analysere pro- og retraksjon i høyre frambein under longering og ridning. Hestene ble først longert (L1) og deretter ridd (R1, R2) før de igjen ble longert (L2) etter ridning. Smertesensitivitet og muskeltonus ble registrert før L1 og etter R2 med et trykkalgometer og Bjerkemetoden (Oslo, Norge). Atferdsobservasjoner ble filmet og registrert i intervaller ved hjelp av et fastsatt etogram for L1, R1, R2 og L2. Hode- og nakkeposisjon (HNP1-HNP6) ble vurdert samtidig som andre atferdsobservasjoner ut fra en på forhånd fastsatt skala. Summen av positive atferder økte signifikant relativt til en lavere hode- og nakkeposisjon og den høyeste summen av positive atferder fant vi ved HNP5 og HNP6 i gangarten skritt. Samarbeidsviljen, evne til arbeid og kvalitet på gangarten økte gjennom treningsøkten og viste signifikante forskjeller på tvers av de ulike hode- og nakkeposisjonene. Smertesensitivitet og muskeltonus gikk ned etter ridning og det var en signifikant forskjell i ryggpartiet til hestene. Vi fant ingen effekt av Bjerkemetoden for verken smertesensitivitet eller muskeltonus. Hestene viste størst rekkevidde for bevegelse i trav under L1 og lavest rekkevidde under R2 i skritt. Resultatene diskuteres opp mot det innledende litteraturstudiet og konkluderer med at treningsmodellen viser en tydelig positiv effekt for hestens velferd under rytter. Metoden setter hestene i en positiv mental tilstand samtidig som den viser tegn til fysiske forbedringer for hestene i forsøket. The study has been analysing the correlation between behavioural, physical and biomechanical effects of a systematic riding method that aims to loosen up and build up the core muscles while it has a stress-reducing effect. The aim was to look at behavioural changes through the training session and their relationship to head and neck position, pain sensitivity and muscle tone before and after riding, and the biomechanical movement patterns of the horses during riding. The hypothesis suggests that a deeper head and neck position is resulting in increased positive behavior signals, while it is predicted that the horses will have a decrease in pain sensitivity and a change in muscle tone depending from the horse’s base point (hypertonic/spastic). The horses (n = 8) were equipped with analysis tools from Qualisys and X-IO to analyse pro- and retraction in the right front leg during lunging and riding. The horses were first lunged (L1) and then ridden (R1, R2) before they again became lunged (L2) after riding. Pain sensitivity and muscle tone was recorded before L1 and after R2 with pressure algometry and the Bjerke-method (Oslo, Norway). Behavioural observations were filmed and recorded at intervals by a fixed etogram for L1, R1, R2 and L2. Head and neck position (HNP1-HNP6) were evaluated at the same time from a predetermined scale. The sum of positive behaviours increased significantly relative to a lower head and neck position, and the highest sum of positive behaviour we found at HNP5 and HNP6 in walk. Willingness to work, ability to work and quality of gait increased through the training session and showed significant differences across the various head and neck positions. Pain sensitivity and muscle tone went down after riding and there was a significant difference in the back of the horses. We found no effect of Bjerke-method for neither pain sensitivity nor muscle tone. The horses showed the greatest range of motion in trot under L1 and lowest range in walk under R2. The findings are discussed against the initial literature study and conclude that the training model shows a clear positive effect on the horse's welfare while ridden. This method puts the horses in a positive mental state while showing signs of physical improvements for the horses in the experiment.M-H

Utviklingen av en velferdsvennlig treningsmetode for sportshester: atferd, trykkalgometri og biomekaniske målinger

Det er blitt analysert sammenhengen mellom atferdsmessige, fysiske og biomekaniske effekter for en systematisk ridemetode som tar sikte på å løsgjøre og bygge opp kjernemuskulaturen samtidig som den har en stressreduserende effekt. Målet var å se på atferdsmessige forandringer under denne ridningen og deres relasjon til hode- og nakkeposisjon, smertesensitivitet og muskeltonus, før og etter ridning, samt bevegelsesmønsteret til hestene under ridningen. Hypotesen foreslår at en dypere hode- og nakkeposisjon medfører økte positive atferdssignaler samtidig som det predikeres at hestene vil ha en nedgang i smertesensitivitet og en forandring i muskeltonus gitt ut fra hesten utgangspunkt (hypertonisk/spastisk). Hestene (n = 8) ble utstyrt med analyseverktøy fra Qualisys og X-IO for å analysere pro- og retraksjon i høyre frambein under longering og ridning. Hestene ble først longert (L1) og deretter ridd (R1, R2) før de igjen ble longert (L2) etter ridning. Smertesensitivitet og muskeltonus ble registrert før L1 og etter R2 med et trykkalgometer og Bjerkemetoden (Oslo, Norge). Atferdsobservasjoner ble filmet og registrert i intervaller ved hjelp av et fastsatt etogram for L1, R1, R2 og L2. Hode- og nakkeposisjon (HNP1-HNP6) ble vurdert samtidig som andre atferdsobservasjoner ut fra en på forhånd fastsatt skala. Summen av positive atferder økte signifikant relativt til en lavere hode- og nakkeposisjon og den høyeste summen av positive atferder fant vi ved HNP5 og HNP6 i gangarten skritt. Samarbeidsviljen, evne til arbeid og kvalitet på gangarten økte gjennom treningsøkten og viste signifikante forskjeller på tvers av de ulike hode- og nakkeposisjonene. Smertesensitivitet og muskeltonus gikk ned etter ridning og det var en signifikant forskjell i ryggpartiet til hestene. Vi fant ingen effekt av Bjerkemetoden for verken smertesensitivitet eller muskeltonus. Hestene viste størst rekkevidde for bevegelse i trav under L1 og lavest rekkevidde under R2 i skritt. Resultatene diskuteres opp mot det innledende litteraturstudiet og konkluderer med at treningsmodellen viser en tydelig positiv effekt for hestens velferd under rytter. Metoden setter hestene i en positiv mental tilstand samtidig som den viser tegn til fysiske forbedringer for hestene i forsøket. The study has been analysing the correlation between behavioural, physical and biomechanical effects of a systematic riding method that aims to loosen up and build up the core muscles while it has a stress-reducing effect. The aim was to look at behavioural changes through the training session and their relationship to head and neck position, pain sensitivity and muscle tone before and after riding, and the biomechanical movement patterns of the horses during riding. The hypothesis suggests that a deeper head and neck position is resulting in increased positive behavior signals, while it is predicted that the horses will have a decrease in pain sensitivity and a change in muscle tone depending from the horse’s base point (hypertonic/spastic). The horses (n = 8) were equipped with analysis tools from Qualisys and X-IO to analyse pro- and retraction in the right front leg during lunging and riding. The horses were first lunged (L1) and then ridden (R1, R2) before they again became lunged (L2) after riding. Pain sensitivity and muscle tone was recorded before L1 and after R2 with pressure algometry and the Bjerke-method (Oslo, Norway). Behavioural observations were filmed and recorded at intervals by a fixed etogram for L1, R1, R2 and L2. Head and neck position (HNP1-HNP6) were evaluated at the same time from a predetermined scale. The sum of positive behaviours increased significantly relative to a lower head and neck position, and the highest sum of positive behaviour we found at HNP5 and HNP6 in walk. Willingness to work, ability to work and quality of gait increased through the training session and showed significant differences across the various head and neck positions. Pain sensitivity and muscle tone went down after riding and there was a significant difference in the back of the horses. We found no effect of Bjerke-method for neither pain sensitivity nor muscle tone. The horses showed the greatest range of motion in trot under L1 and lowest range in walk under R2. The findings are discussed against the initial literature study and conclude that the training model shows a clear positive effect on the horse's welfare while ridden. This method puts the horses in a positive mental state while showing signs of physical improvements for the horses in the experiment

Developing a welfare-friendly training method for sport horses: behavior, pressure algometry and biomechanical measurements

Det er blitt analysert sammenhengen mellom atferdsmessige, fysiske og biomekaniske effekter for en systematisk ridemetode som tar sikte på å løsgjøre og bygge opp kjernemuskulaturen samtidig som den har en stressreduserende effekt. Målet var å se på atferdsmessige forandringer under denne ridningen og deres relasjon til hode- og nakkeposisjon, smertesensitivitet og muskeltonus, før og etter ridning, samt bevegelsesmønsteret til hestene under ridningen. Hypotesen foreslår at en dypere hode- og nakkeposisjon medfører økte positive atferdssignaler samtidig som det predikeres at hestene vil ha en nedgang i smertesensitivitet og en forandring i muskeltonus gitt ut fra hesten utgangspunkt (hypertonisk/spastisk). Hestene (n = 8) ble utstyrt med analyseverktøy fra Qualisys og X-IO for å analysere pro- og retraksjon i høyre frambein under longering og ridning. Hestene ble først longert (L1) og deretter ridd (R1, R2) før de igjen ble longert (L2) etter ridning. Smertesensitivitet og muskeltonus ble registrert før L1 og etter R2 med et trykkalgometer og Bjerkemetoden (Oslo, Norge). Atferdsobservasjoner ble filmet og registrert i intervaller ved hjelp av et fastsatt etogram for L1, R1, R2 og L2. Hode- og nakkeposisjon (HNP1-HNP6) ble vurdert samtidig som andre atferdsobservasjoner ut fra en på forhånd fastsatt skala. Summen av positive atferder økte signifikant relativt til en lavere hode- og nakkeposisjon og den høyeste summen av positive atferder fant vi ved HNP5 og HNP6 i gangarten skritt. Samarbeidsviljen, evne til arbeid og kvalitet på gangarten økte gjennom treningsøkten og viste signifikante forskjeller på tvers av de ulike hode- og nakkeposisjonene. Smertesensitivitet og muskeltonus gikk ned etter ridning og det var en signifikant forskjell i ryggpartiet til hestene. Vi fant ingen effekt av Bjerkemetoden for verken smertesensitivitet eller muskeltonus. Hestene viste størst rekkevidde for bevegelse i trav under L1 og lavest rekkevidde under R2 i skritt. Resultatene diskuteres opp mot det innledende litteraturstudiet og konkluderer med at treningsmodellen viser en tydelig positiv effekt for hestens velferd under rytter. Metoden setter hestene i en positiv mental tilstand samtidig som den viser tegn til fysiske forbedringer for hestene i forsøket. The study has been analysing the correlation between behavioural, physical and biomechanical effects of a systematic riding method that aims to loosen up and build up the core muscles while it has a stress-reducing effect. The aim was to look at behavioural changes through the training session and their relationship to head and neck position, pain sensitivity and muscle tone before and after riding, and the biomechanical movement patterns of the horses during riding. The hypothesis suggests that a deeper head and neck position is resulting in increased positive behavior signals, while it is predicted that the horses will have a decrease in pain sensitivity and a change in muscle tone depending from the horse’s base point (hypertonic/spastic). The horses (n = 8) were equipped with analysis tools from Qualisys and X-IO to analyse pro- and retraction in the right front leg during lunging and riding. The horses were first lunged (L1) and then ridden (R1, R2) before they again became lunged (L2) after riding. Pain sensitivity and muscle tone was recorded before L1 and after R2 with pressure algometry and the Bjerke-method (Oslo, Norway). Behavioural observations were filmed and recorded at intervals by a fixed etogram for L1, R1, R2 and L2. Head and neck position (HNP1-HNP6) were evaluated at the same time from a predetermined scale. The sum of positive behaviours increased significantly relative to a lower head and neck position, and the highest sum of positive behaviour we found at HNP5 and HNP6 in walk. Willingness to work, ability to work and quality of gait increased through the training session and showed significant differences across the various head and neck positions. Pain sensitivity and muscle tone went down after riding and there was a significant difference in the back of the horses. We found no effect of Bjerke-method for neither pain sensitivity nor muscle tone. The horses showed the greatest range of motion in trot under L1 and lowest range in walk under R2. The findings are discussed against the initial literature study and conclude that the training model shows a clear positive effect on the horse's welfare while ridden. This method puts the horses in a positive mental state while showing signs of physical improvements for the horses in the experiment.M-H

Effect of Mechanical Ventilation on Accidental Hydrogen Releases—Large-Scale Experiments

This paper presents a series of experiments on the effectiveness of existing mechanical ventilation systems during accidental hydrogen releases in confined spaces, such as underground garages. The purpose was to find the mass flow rate limit, hence the TPRD diameter limit, that will not require a change in the ventilation system. The experiments were performed in a 40 ft ISO container in Norway, and hydrogen gas was used in all experiments. The forced ventilation system was installed with a standard 315 mm diameter outlet. The ventilation parameters during the investigation were British Standard with 10 ACH and British Standard with 6 ACH. The hydrogen releases were obtained through 0.5 mm and 1 mm nozzles from different hydrogen reservoir pressures. Both types of mass flow, constant and blowdown, were included in the experimental matrix. The analysis of the hydrogen concentration of the created hydrogen cloud in the container shows the influence of the forced ventilation on hydrogen releases, together with TPRD diameter and reservoir pressure. The generated experimental data will be used to validate a CFD model in the next step

Experimental Study of Deflagration to Detonation Transition in Hydrogen-Air Mixtures

This dataset contains high speed videos and pressure recordings from DDT experiments in hydrogen-air mixtures. The experimental setup and method is given in the reference below. The experimental setup is given in the excel-table. Details are given in the README.txt file.<br><br>Abstract of thesis:<br>Gas explosions in a square channel have been investigated with a main focus on the deflagration<br>to detonation transition (DDT). The gas mixtures were hydrogen and air at different concentrations.<br>This work have been motivated by issues of process safety and hydrogen infrastructure<br>development. There is a need to understand the deflagration to detonation transition from a<br>safety perspective. Recent accident have shown possibilities of DDT in premixed fuel and air.<br>At present there are no software tools capable of predicting DDT in real scenarios, and there is<br>a need to produce accurate experimental data for validation, but also a better understanding of<br>the physics related to DDT.<br>The experiments presented in this thesis were performed in a square channel with transparent<br>side walls and one obstacle. The obstacle was placed 1m from the closed ignition end, and the<br>first results chapter presents the experimental study of flame propagation from ignition up to the<br>obstacle. The ignition source was both a single spark and a distributed ignition, were the latter<br>was assumed to produce a 2 dimensional flame front. The main conclusion of this study was<br>that the 2D assumption was only valid up to the point of tulip flame formation.<br>The study of DDT was divided in two parts, one in homogeneous gas mixtures, the other<br>regarding inhomogeneous gas mixtures. The homogeneous gas mixture experiments showed<br>that transverse waves were important for the DDT, but also that these waves originated from far<br>behind the leading tip of the deflagration. This conclusion was also found in a numerical study<br>using the in-house FLIC code developed by Dr. Vaagsaether.<br>The study of inhomogeneous gas mixtures were done to investigate if inhomogeneities increased<br>the likeliness of DDT. The conclusion was that it was not the case in this particular<br>setup and method. However, other interesting results were found regarding detonation propagation<br>in layers of reactants bound by a wall and a layer of air. The propagation mechanism of<br>detonations in a reactive layer was also studied using the FLIC code, where it was observed a<br>expansion effect and a merging of triple points at the top wall. This was qualitatively similar as<br>the experimental results.<br

Effect of Mechanical Ventilation on Accidental Hydrogen Releases—Large-Scale Experiments

This paper presents a series of experiments on the effectiveness of existing mechanical ventilation systems during accidental hydrogen releases in confined spaces, such as underground garages. The purpose was to find the mass flow rate limit, hence the TPRD diameter limit, that will not require a change in the ventilation system. The experiments were performed in a 40 ft ISO container in Norway, and hydrogen gas was used in all experiments. The forced ventilation system was installed with a standard 315 mm diameter outlet. The ventilation parameters during the investigation were British Standard with 10 ACH and British Standard with 6 ACH. The hydrogen releases were obtained through 0.5 mm and 1 mm nozzles from different hydrogen reservoir pressures. Both types of mass flow, constant and blowdown, were included in the experimental matrix. The analysis of the hydrogen concentration of the created hydrogen cloud in the container shows the influence of the forced ventilation on hydrogen releases, together with TPRD diameter and reservoir pressure. The generated experimental data will be used to validate a CFD model in the next step

Validation of a Hydrogen Jet Fire Model in FDS

Hydrogen jet fire occurs with high probability when hydrogen leaks from high-pressure equipment. The hydrogen jet fire is characterized by its high velocity and energy. Computational Fluid Dynamics (CFD) numerical analysis is a prominent way to predict the potential hazards associated with hydrogen jet fire. Validation of the CFD model is essential to ensure and quantify the accuracy of numerical results. This study focuses on the validation of the hydrogen jet fire model using Fire Dynamic Simulation (FDS). Hydrogen release is modeled using high-speed Lagrangian particles, released from a virtual nozzle, thus avoiding the modeling of the actual nozzle. The mesh size sensitivity analysis of the model is carried out in a container-size domain with 0.04m – 0.08m resolution of the jet. The model is validated by comparing gas temperatures and heat fluxes with test data. The promising results demonstrated that the model could predict the hazardous influence of the jet fire