News Article | November 29, 2016
MMI Engineering Ltd (MMI) is pleased to announce the appointment of Dr. John Evans as its new Managing Director. Since 2010, Dr. Evans has successfully managed MM Engineering's Aberdeen office while fulfilling the role of technical safety lead - an area in which he has more than 25 years of professional experience. In 2015, Dr. Evans was promoted to UK Operations Manager. His combined role saw him retain management of the multi-disciplinary teams in the Aberdeen office, however, his responsibilities were increased to cover the whole of MMI's operations in the UK. Upon Dr. Evans' promotion to Managing Director, Dr. Simon Thurlbeck, MMI's former Managing Director and founder of their UK operations, stated, "I believe John is the right person to lead MMI through the next stage of the Company's evolution. Since he joined us, he has demonstrated his ability to not only deliver first class solutions to his clients, but to influence and inspire those around him. He is the perfect leader for our firm, which is founded at all levels on outstanding technical competence and outstanding client service." MMI currently has offices in the UK, US, Malaysia and Australia. Founded in 2001, the company provides technical consulting services to a wide range of clients across a host of industry sectors, including oil and gas, water, nuclear, security, and defence, specialising in the identification, assessment and management of man-made and natural hazards by the application of a blend of expertise drawn from a range of scientific and engineering backgrounds. Dr. Thurlbeck will be concentrating his efforts on his professional practice (Major Hazards Risk Management) as well as providing mentoring and business development support across all MMI's offices. He recently helped found The Hydrocarbon Passive Fire Protection Network (PFPNet), an industry group aimed at improving knowledge and awareness of, and developing best practices for, passive fire protection, and he will be placing this at the core of his consulting activities. Upon accepting his new role, Dr. Evans stated, "I am honoured to assume the role as Managing Director of MMI. Simon has led the company from strength-to-strength, growing our capabilities and establishing our presence in several key industries and global locations. It's thanks to him and our employees, many of whom have reputations as thought leaders in their respective sectors, that so many of our clients trust us to solve their more difficult problems. In the current business climate, it is my intention to build upon MMI's core areas of Fluid Systems and Heat Transfer, Asset Management, Safety, Structural Integrity, and Fire Protection. Our company has a history of providing innovative solutions to some of our clients' more challenging needs, and I will be advocating this as we continue to ensure that MMI is recognised as one of the world's leading, independent, consulting companies." For more information about MMI Engineering, please visit: http://www.mmiengineering.com. MMI Engineering is a technical consulting firm providing services to a wide range of industries including Oil & Gas, Nuclear, Renewable Energy, Petrochemical, Defence & Security and Aerospace. With offices spanning all the major time zones we provide clients around the globe with technical expertise delivered with a continuous commitment to meet and exceed our client's requirements.
Munoz-Garcia E.,MMI Engineering Ltd
Society of Petroleum Engineers - SPE Offshore Europe Conference and Exhibition, OE 2013 | Year: 2013
Passive fire protection (PFP) has been used in the Oil & Gas industry for many years as a method to avoid/delay global collapse of offshore installations. However location of PFP has normally been based on simplistic assumptions, standards, guidance and methods that do not always consider the real response of the structure to fire. The resulting PFP schemes can be conservative leading to unnecessary cost to the Operator in terms of application and maintenance costs. More importantly, there is the potential for the PFP scheme to be insufficient for the actual fire hazards which will increase the level of risk for the personnel on board. Fire induced progressive collapse is a function of the level of redundancy of a structure, it is for this reason that redundancy analyses have sometimes been used as a simplistic method to calculate the level of PFP required. However this method does not take into account the size of the fire threat against which the PFP is designed and could lead to less than conservative results as it only considers removing one member of the structure at a time, without considering reduction in the strength of the surrounding members as they are also being heated by the fire. Performance based fire collapse analysis provides an understanding of the response of the individual members as well as the entire structural system to fire. Understanding the failure mechanisms, susceptibility to progressive collapse of the structure, and key members that must remain in place during an accident situation allows for the optimisation of the PFP scheme, protecting only the required members while allowing for local failure of redundant members. The present paper provides a comparison between the different methods, and provides case studies that have resulted in optimum PFP schemes linked to design fires based on acceptable risk levels. Copyright 2013, Society of Petroleum Engineers.
King F.,Integrity Corrosion Consulting |
Burt D.,MMI Engineering Ltd. |
Ganeshalingam J.,MMI Engineering Ltd. |
Gardner P.,MMI Engineering Ltd. |
And 3 more authors.
Corrosion Engineering Science and Technology | Year: 2014
Failure of high level waste/spent fuel containers is most likely to occur as a result of mechanical overload following a period of corrosion that results in a reduction of the wall thickness and/or the degradation of the material properties. There can be significant interaction between the mechanical loads and the corrosion processes to which a disposal container is subjected which, in turn, can influence the mode and time of failure. Here, these interactions are illustrated for a single shell, carbon steel spent fuel container during its entire life cycle, from the time of manufacture through to the long term behaviour in a bentonite backfilled geological disposal facility. The evolution of the structural integrity of the container is illustrated through the use of failure assessment diagrams. © 2014 Institute of Materials, Minerals and Mining.
Emery R.,MMI Engineering Ltd.
Institution of Chemical Engineers Symposium Series | Year: 2014
Quantitative risk assessments (QRAs) for offshore oil and gas exploration and production assets are commonly used in the industry to demonstrate that risks are within tolerable limits. The results of these QRAs are included in an installation's Operations Safety Case, which is prepared in response to the requirements of Regulation 7 of the Offshore Installations (Safety Case) Regulations 2005 [SCR 2005]. These results provide part of the demonstration that the risks are managed to ALARP and are also used as input into the Justification for Continued Operations. A limitation of these assessments, however, is that a realistic comparison between assets is often not possible since methods, input data and assumptions vary from one QRA to another, in some cases quite widely. These variations may include the use of differing leak frequency databases, differing parts count definitions, ignition models, and fatality and impairment probabilities. In addition, QRAs do not focus on potential asset, or environmental consequences which are of significant interest to operators and equity partners. This paper presents a methodology for assessing Major Incident Frequencies to enable a realistic comparison, on a like for like basis, of a range of asset types, which have been assessed using differing QRA methodologies. The methodology presented within this paper has been applied to various assets including fixed manned and unmanned installations, FPSO's and FSO's. The results indicate that the methodology developed is sufficiently robust to allow a meaningful comparison to be made between different types of assets, and provides an improved estimation of the overall major incident risk frequency compared with that which is typically presented in installation specific safety cases. © IChemE.
Malkeson S.P.,MMI Engineering Ltd. |
Chakraborty N.,Northumbria University
Flow, Turbulence and Combustion | Year: 2013
Three-dimensional Direct Numerical Simulations of statistically planar turbulent stratified flames at global equivalence ratios < φ > = 0.7 and < φ > = 1.0 have been carried out to analyse the statistical behaviour of the transport of co-variance of the fuel mass fraction Y F and mixture fraction ξ (i.e. Y″ Fξ″̃ = ρ Y″Fξ″ ̄/ρ̄) for Reynolds Averaged Navier Stokes simulations where q̄, q̃ = ρq̄/ρ̄ and q″= q - q̃ are Reynolds averaged, Favre mean and Favre fluctuation of a general quantity q with ρ being the gas density and the overbar suggesting a Reynolds averaging operation. It has been found that existing algebraic expressions may not capture the statistical behaviour of Y″Fξ″̃ with sufficient accuracy in low Damköhler number combustion and therefore, a transport equation for Y″Fξ″̃ may need to be solved. The statistical behaviours of Y″Fξ″̃ and the unclosed terms of its transport equation (i.e. the terms originating from turbulent transport T1, reaction rate T4 and molecular dissipation (-D2)) have been analysed in detail. The contribution of T1 remains important for all cases considered here. The term T 4 acts as a major contributor in < φ > = 1.0 cases, but plays a relatively less important role in < φ > = 0.7 cases, whereas the term (-D2) acts mostly as a leading order sink. Through an a-priori DNS analysis, the performances of the models for T1, T 4 and (-D2) have been addressed in detail. A model has been identified for the turbulent transport term T1 which satisfactorily predicts the corresponding term obtained from DNS data. The models for T4, which were originally proposed for high Damköhler number flames, have been modified for low Damköhler combustion. Predictions of the modified models are found to be in good agreement with T 4 obtained from DNS data. It has been found that existing algebraic models for D2 =2ρD∇Y″ F∇ξ″̄ (where D is the mass diffusivity) are not sufficient for low Damköhler number combustion and therefore, a transport equation may need to be solved for the cross-scalar dissipation rate ε̃YΞ = D∇Y″F∇ξ″̄ for the closure of the Y″Fξ″̃ transport equation. © 2012 Springer Science+Business Media Dordrecht.
Wacks D.H.,Northumbria University |
Malkeson S.P.,MMI Engineering Ltd. |
Chakraborty N.,Northumbria University
Numerical Heat Transfer; Part A: Applications | Year: 2016
Three-dimensional direct numerical simulations (DNS) data of statistically planar turbulent spray flames propagating into monodisperse droplets for different values of droplet diameter ad and droplet equivalence ratio ϕd have been used to analyze the statistical behavior of the fuel mass fraction variance (Formula presented.) and its transport in the context of Reynolds-averaged Navier–Stokes (RANS) simulations. The algebraic closure, which was previously derived for high Damköhler number turbulent stratified mixture combustion, has been shown not to capture statistical behavior of (Formula presented.) for turbulent spray flames, because the underlying assumptions behind the original modeling are invalid for the cases considered in this analysis. The modeling of the unclosed terms of the variance (Formula presented.) transport equation (i.e., the turbulent transport term T1, the reaction rate contribution T3, the evaporation contribution T4, and the dissipation rate term –D2) has been analyzed in the context of RANS simulations. The models previously proposed in the context of turbulent gaseous stratified flames have been considered here to assess their suitability for turbulent spray flames. Model expressions have been identified for (Formula presented.) and −D2 which have been shown to perform satisfactorily in all cases considered in the current study. However, the model previously proposed for T3 in the context of turbulent gaseous stratified flames has been found to be inadequate for turbulent spray flames and further consideration of the modeling of this unclosed term is therefore necessary. 2016 Copyright © Taylor & Francis Group, LLC
Sun R.,MMI Engineering Ltd. |
Burgess I.W.,University of Sheffield |
Huang Z.,Brunel University |
Dong G.,MMI Engineering Ltd.
Engineering Structures | Year: 2015
A numerical procedure has been developed to model the sequences of failure which can occur within steel beam-to-column connections under fire conditions. In this procedure two recent developments, a static-dynamic solution process and a general component-based connection element, have been combined within the software Vulcan in order to track the sequence of local failures of the connections which lead to structural progressive collapse in fire. In particular the procedure developed can be used to investigate the structural behaviour in fire, particularly the ductility and fracture of different parts of the steel-to-steel connections, and the influence of the connections on the progressive collapse resistance of steel frames in fire. In the component-based connection model, a connection is represented as an assembly of "bolt-rows" composed of components representing different zones of mechanical behaviour whose stiffness, strength, ductility and fracture under changing temperatures can be adequately represented for global modelling. The potential numerical instabilities induced by fractures of individual connection's components can be overcome by the use of alternate static and dynamic analyses. The transfer of data between the static and dynamic analyses allows a seamless alternation between these two procedures to take place. Accuracy and stability of the calculations can be ensured in the dynamic phase, provided that the time steps are set sufficiently small. This procedure has the capacity of tracking the sequence of local failures (fractures of connection components, detachment and motion of disengaging beams, etc.) which lead to final collapse. Following an illustrative case study of a two-bay by two-storey frame, the effect of ductility of connections on the collapse resistance of steel frames in fire is demonstrated in two case studies of a generic multi-storey frame. It is shown that the analytical process is an effective tool in tackling the numerical problems associated with the complex structural interactions and discontinuous failures which can affect a steel or composite frame in fire, potentially leading to progressive collapse. It can be seen that both tensile and compressive ductility in the connections make a contribution to the fire resistance of the beams. Preventing the detachment of steel beams in fire can be achieved by inducing greater ductility into their connections. Combined with appropriate component-based connection models, this procedure can be adopted in performance-based fire-resistant design to assess the ductility requirements of steel connections. © 2015 Elsevier Ltd.
Sun R.,MMI Engineering Ltd |
Burgess I.W.,University of Sheffield
Engineering Structures | Year: 2016
In this paper a simplified analytical method to assess the ductility demand on connections according to fire resistance requirements is developed on the basis of fundamental structural mechanics principles. An objective is to enable the development of a viable method to allow engineers to take the ductility of connections into account in design practice. Numerical finite element simulations of the single beam model were also performed to validate the simplified analytical model and reveal the important parameters that can influence the ductility demand within the connections. Using both analytical and numerical methods, the principal factors which influence the ductility demand of a connection, such as the span of the connected beam and the required connection strength, are also assessed. It is shown that:. 1.The compressive ductility of connections is helpful in reducing the push-out of perimeter columns and the possibility of local buckling of beams.2.Provision of high tensile deformation capacity allows large deflection in the beam, substantially reduces catenary forces on the connections, and consequently reduces the risk of structural collapse in fire.3.The ductility demand of the connection is closely related to its stiffness and strength, as well as to the slenderness and load ratio of the connected beam. © 2016 Elsevier Ltd.
Katragadda M.,Northumbria University |
Malkeson S.,MMI Engineering Ltd. |
Chakraborty N.,Northumbria University
International Journal of Spray and Combustion Dynamics | Year: 2014
A simple chemistry based three-dimensional Direct Numerical Simulations (DNS) database of freely propagating statistically planar turbulent premixed flames with a range of different values of Karlovitz number Ka, turbulent Reynolds number Ret, heat release parameter τ and global Lewis number Le has been used for the modelling of the curvature term of the generalised Flame Surface Density (FSD) transport equation in the context of Reynolds Averaged Navier Stokes (RANS) simulations. The curvature term has been split into the contributions arising due to the reaction and normal diffusion components of displacement speed (i.e. T1) and the term arising due to the tangential diffusion component of displacement speed (i.e. T 2). Subsequently, the sub-terms (i.e. T1 and T 2) of the curvature contribution to the FSD transport have been split into the closed (i.e. T1r and T2r) and unclosed (i.e. T1ur and T2ur) components. It has been found that T 2 remains deterministically negative throughout the flame brush. However, the qualitative behaviour of T1 changes significantly depending upon the values of Ka, Ret and Le. Detailed physical explanations have been provided for the observed behaviours of the components of the curvature term. Moreover, it has been observed that the closed contributions of T1 and T2 (i.e. T1r and T 2r) remains negligible in comparison to the unclosed contributions (i.e. T1ur and T2ur). Suitable model expressions have been identified for T1ur and T2ur in the context of RANS simulations, which are shown to perform satisfactorily in all cases considered in the current analysis, accounting for the variations in Ka, Ret, τ and Le.
MMI ENGINEERING Ltd | Date: 2015-01-27
A method of manufacturing a sub-aqua foundation including: