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Offshore industries encounter severe production downtime due to high liquid carryovers in the T-junction. The diameter ratio and flow regime can significantly affect the excess liquid carryovers. Unfortunately, regular and reduce T-junctions have low separation efficiencies. Ansys as a commercial computational fluid dynamics (CFD) software was used to model and numerically inspect a novel diverging T-junction design. The purpose of diverging T-junction is to merge the specific characteristics of regular and reduced T-junctions, ultimately increasing separation efficiency. The purpose of this study is to numerically compute the separation efficiency for five distinct diverging T-junctions for eight different velocity ratios. The results were compared to regular and converging T-junctions.

Air-water slug flow was simulated with the help of the volume of the fluid model, coupled with the K-epsilon turbulence model to track liquid-gas interfaces.

The results of this study indicated that T-junctions with upstream and downstream diameter ratio combinations of 0.8–1 and 0.5–1 achieved separation efficiency of 96% and 94.5%, respectively. These two diverging T-junctions had significantly higher separation efficiencies when compared to regular and converging T-junctions. Results also revealed that over-reduction of upstream and downstream diameter ratios below 0.5 and 1, respectively, lead to declination in separation efficiency.

The present study is constrained for air and water as working fluids. Nevertheless, the results apply to other applications as well.

The proposed T-junction is intended to reduce excessive liquid carryovers and frequent plant shutdowns. Thus, lowering operational costs and enhancing separation efficiency.

Higher separation efficiency achieved by using diverging T-junction enabled reduced production downtimes and resulted in lower maintenance costs.

A novel T-junction design was proposed in this study with a separation efficiency of higher than 90%. High separation efficiency eliminates loss of time during shutdowns and lowers maintenance costs. Furthermore, limitations of this study were also addressed as the lower upstream and downstream diameter ratio does not always enhance separation efficiency.

In plethora of petroleum, chemical and heat transfer applications, T-junction is often used to partially separate gas from other fluids, to reduce work burden on other separating equipment. The abundance of liquid carryovers from the T-junction side arm is the cause of production downtime in terms of frequent tripping of downstream equipment train. Literature review revealed that regular and reduced T-junctions either have high peak liquid carryovers (PLCs) or the liquid appears early in the side arm [liquid carryover threshold (LCT)]. The purpose of this study is to harvest the useful features of regular and reduced T-junction and analyze diverging T-junction having upstream and downstream pipes.

Volume of fluid as a multiphase model, available in ANSYS Fluent, was used to simulate air–water slug flow in five diverging T-junctions for eight distinct velocity ratios. PLCs and LCT were chosen as key performance indices.

The results indicated that T (0.5–1) and (0.8–1) performed better as low liquid carryovers and high LCT were achieved having separation efficiencies of 96% and 94.5%, respectively. These two diverging T-junctions had significantly lower PLCs and high LCT when compared to other three T-junctions. Results showed that the sudden reduction in the side arm diameter results in high liquid carryovers and lower LCT. Low water and air superficial velocities tend to have low PLC and high LCT.

This study involved working fluids air and water but applies to other types of fluids as well.

The novel T-junction design introduced in this study has significantly higher LCT and lower PLC. This is an indication of higher phase separation performance as compared to other types of T-junctions. Because of lower liquid take-offs, there will be less frequent downstream equipment tripping resulting in lower maintenance costs. Empirical correlations presented in this study can predict fraction of gas and liquid in the side arm without having to repeat the experiment.

Maintenance costs and production downtime can be significantly reduced with the implication of diverging T-junction design.

The presented study revealed that the diameter ratio has a significant impact on PLC and LCT. It can be concluded that novel T-junction designs, T2 and T3, achieved high phase separation; therefore, it is favorable to use in the industry. Furthermore, a few limitations in terms of diameter ratio are also discussed in detail.

This chapter discusses how attachment theory, a theory that provides insight into the processes through which psychological and emotional bonds are developed in relationships, can be useful for understanding mentoring relationships. We develop a conceptual model emphasizing how attachment-related constructs and their relationships with mentors’ and protégés’ behaviors and emotions influence each phase of a mentoring relationship. Recognizing reciprocity in the mentoring process, the model also explains how the interpersonal dynamics of the mentor–protégé relationship influence the benefits gained by both partners. Propositions for future research on mentoring relationships are provided. We contend that examining mentoring through the lens of attachment theory can increase our understanding of the underlying factors or mechanisms that determine individuals’ involvement in mentoring relationships and differentiate successful from unsuccessful mentoring relationships. The research and practical implications are discussed.

The purpose of this paper is to present numerical results about phase separation of binary fluid mixtures quenched by contact with cold walls.

The thermal phase separation is simulated by using a hybrid lattice Boltzmann method that solves the continuity and the Navier‐Stokes equations. The equations for energy and concentration are solved by using a finite‐difference scheme. This approach provides a complete description of the thermo‐hydrodynamic effects in the mixture.

A rich variety of domain patterns are found depending on the viscosity and on the heat conductivity of the mixture. Ordered lamellar structures are observed at high viscosity while domains rounded in shape dominate the phase separation at low viscosity, where two scales characterize the growth of domains.

The present approach provides a numerical method that can be extended to other systems such as liquid‐vapor or lamellar systems. Moreover, a three‐dimensional study can give a complete picture of thermo‐hydrodynamic effects.

This paper provides a consistent thermodynamic theoretical framework for a binary fluid mixture and a numerically stable method to simulate them.

This paper aims to consider the thrust force generated by two plunging and pitching plates in a tandem configuration in forward flight to find out the configuration that maximizes the propulsive efficiency with high-enough time-averaged lift force.

To that end, the Navier–Stokes equations for the incompressible and two-dimensional flow at Reynolds number $500 are solved. As the number of parameters is quite large, the case of constant separation between the plates (half their chord length), varying seven non-dimensional parameters related to the phase shift between the heaving motion of the foils, the phase lag between pitch and heave of each plate independently and the frequency and amplitude of the heaving and pitching motions are considered. This analysis complements some other recent studies where the separation between the foils has been used as one of the main control parameters.

It is found that the propulsive efficiency is maximized for a phase shift of 180° (counterstroking), when the reduced frequency is 2.2 and the Strouhal number based on half the plunging amplitude is 0.17, the pitching amplitude is 25° and when pitch leads heave by 135° in both the fore -plate and the hind plate. The propulsive efficiency is about 20 per cent, just a bit larger than that of an isolate plate with the same motion as the fore-plate, but the corresponding lift force is negligible for a single plate. The paper discusses this vortical flow structure in relation to other less efficient ones. Finally, the effect of the separation between the plates and the Reynolds number is also briefly discussed.

The kinematics of two flapping plates in tandem configuration that maximizes the propulsive efficiency are characterized discussing physically the associated vortical flow structures in comparison with less efficient kinematic configurations. A much larger number of parameters in the optimization procedure than in previous related works is considered.

In the European project AFLoNext, active flow control (AFC) measures were adopted in the wing tip extension leading edge to suppress flow separation. It is expected that the designed wing tip extension may improve aerodynamic efficiency by about 2 per cent in terms of fuel consumption and emissions. As the leading edge of the wing tip is not protected with high-lift device, flow separation occurs earlier than over the inboard wing in the take-off/landing configuration. The aim of this study is the adoption of AFC to delay wing tip stall and to improve lift-to-drag ratio.

Several actuator locations and AFC strategies were tested with computational fluid dynamics. The first approach was “standard” one with physical modeling of the actuators, and the second one was focused on the volume forcing method. The actuators location and the forcing plane close to separation line of the reference configuration were chose to enhance the flow with steady and pulsed jet blowing. Dependence of the lift-to-drag benefit with respect to injected mass flow is investigated.

The mechanism of flow separation onset is identified as the interaction of slat-end and wing tip vortices. These vortices moving toward each other with increasing angle of attack (AoA) interact and cause the flow separation. AFC is applied to control the slat-end vortex and the inboard movement of the wing tip vortex to suppress their interaction. The separation onset has been postponed by about 2° of AoA; the value of ift-to-drag (L/D) was improved up to 22 per cent for the most beneficial cases.

The AFC using the steady or pulsed blowing (PB) was proved to be an effective tool for delaying the flow separation. Although better values of L/D have been reached using steady blowing, it is also shown that PB case with a duty cycle of 0.5 needs only one half of the mass flow.

Two approaches of different levels of complexity are studied and compared. The first is based on physical modeling of actuator cavities, while the second relies on volume forcing method which does not require detailed actuator modeling. Both approaches give consistent results.

In this paper we develop an integrated model identifying the key factors involved in managing exploratory innovation processes while also maintaining current business models and processes.

We first characterize the problem of innovation as consisting of “the four central problems” organizations face when trying to manage innovation processes (Van de Ven, 1986). We develop an enhanced version of O’Connor’s (2008) Discovery, Incubation and Acceleration (DIA) model by integrating elements of Sanchez’ (2012) theory of architectural isomorphism as well as Markides’ (2008) framework for strategically assessing the benefits of segregation versus integration of innovation processes. We develop and apply our model working with managers in two company contexts to assure the ability of our Integrated Model to identify key organizational and strategic variables that need to be recognized and managed in order to sustain successful exploratory innovation processes.

Reviews of our “Enhanced Integrated Model” with managers in the two companies suggest that our model would help them to recognize and manage key issues that were not addressed adequately in their prior efforts at exploratory innovation.

Our model building process provides a basic template for other research focused on developing normative management models through case-based research. The specific elements included in our Enhanced Integrated Models should provide managers with a useful model for managing exploratory innovation processes.

The purpose of this paper is to analyze the benefits and drawbacks that strategically imposed liminality inflicts upon inter-organizational digitalization efforts within the different phases of its utilization.

This study empirically examines digitalization in a large multinational manufacturing company, Sandvik Machining Solutions, using data that were collected through interviews and a qualitative research design.

This study shows that a liminal space separated from the structures in which one is supposed to inflict changes increases the risk of developing an incompatible system that will be rejected in the incorporation phase. An inter-organizational perspective on liminality thus contributes to our understanding of the benefits and drawbacks that liminal space can pose for the organizations involved.

The study suggests that, in the separation phase, driving change processes by creating liminal spaces could be a way to loosen up rigid resource structures and circumvent network over-embeddedness. Finding the right amount of freedom, ambiguity and community within the liminal space is, however, essential for the transition of information as well as the incorporation of the imposed changes.

Introducing an inter-organizational perspective on liminality contributes to our understanding of the stress that liminal space can place on individuals as well as the individual organization.

The purpose of this paper is to optimize the downrange for hypersonic boost‐glide (HBG) missile under near‐real condition, and to validate the suitability of proposed wall cooling materials.

The trajectory optimization problem is characterized by a boost phase followed by a glide phase. A multi‐phase trajectory optimization tool is adopted to optimize the downrange. The associated optimal control problem has been solved by selecting a direct shooting method. The dynamics has been transcribed to a set of nonlinear constraints and the arising nonlinear programming problem has been solved through a sequential quadratic programming solver. An aerothermodynamics analysis method is introduced to calculate the aerodynamic heating at nose, leading edge, and ventral centerline regions.

HBG missile is suitable for long‐range attack, and the optimal trajectory solved is a novel boost‐glide‐skip trajectory, i.e. boost firstly, glide secondly, and skip at last. The proposed wall materials are valid.

This paper provides further study on the methods of trajectory design and aerothermodynamics analysis for HBG missile.