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Interphase forces between the gas and liquid phases determine many phenomena in bubbly flow. For the interphase forces in a multiphase rotodynamic pump, the magnitude analysis was carried out within the framework of two-fluid model. The purpose of this paper is to clarify the relative importance of various interphase forces on the mixed transport process, and the findings herein will be a base for the future study on the mechanism of the gas blockage phenomenon, which is the most challenging issue for such pumps.

Four types of interphase forces, i.e. drag force, lift force, virtual mass force and turbulent dispersion force (TDF) were taken into account. By comparing with the experiment in the respect of the head performance, the effectiveness of the numerical model was validated. In conditions of different inlet gas void fractions, bubble diameters and rotational speeds, the magnitude analyses were made for the interphase forces.

The results demonstrate that the TDF can be neglected in the running of the multiphase rotodynamic pump; the drag force is dominant in the impeller region and the outlet extended region. The sensitivity analyses of the bubble diameter and the rotational speed were also performed. It is found that larger bubble size is accompanied by smaller predicted drag but larger predicted lift and virtual mass, while the increase of the rotational speed can raise all the interphase forces mentioned above.

This paper has revealed the magnitude information and the relative importance of the interphase forces in a multiphase rotodynamic pump.

Spinning slender bodies are affected by lateral Magnus forces and moments when exposed to cross-flow. The effects occurring for spinning bodies of revolution in combination with stabilising or control surfaces such as canards are not yet fully explained. Therefore the present work aims to investigate the phenomena arising from the interactions of a roll-decoupled guidance unit with a spinning rear body are investigated.

A generic tangential-ogive-cylinder projectile equipped with deflectable canards on a roll-decoupled nose is investigated by means of 3D Reynolds-averaged Navier–Stokes simulations at Mach number 2 for angles of attack up to 22 degrees. Different canard deflection angles up to 9 degrees are considered. Global aerodynamic coefficients as well as local flow fields are analysed to explain the interactions occurring between the roll-decoupled guidance unit and the spinning rear body.

The deflected canards lead to flow interactions resulting in lateral forces and moments even without a spinning motion of the rear part. Depending on the canard deflection angles, these forces act in or against the direction of the classical Magnus effect. For angles of attack smaller than 10 degrees it is possible for the current body geometry to directly superpose the lateral effects resulting from the fins for the non-spinning model with those occurring for the non-finned but spinning model to obtain the total forces and moments acting on a spinning model with canted canards. However, the lateral effects generated on the guidance unit itself are insignificant compared to the canard-induced effects on the rear body.

A detailed analysis of the interaction effects arising from a decoupled guidance unit containing canards with a non-spinning/spinning rear body is performed and the underlying phenomena are revealed.

The purpose of this paper is to examine the ability of the harmonic balance method for predicting the aerodynamic characteristics of rigid finned spinning vehicle.

The aerodynamic characteristics of a rigid four-finned spinning vehicle at Mach number 2.5 and angle of attack of 20 degrees are simulated using the harmonic balance method and the unsteady time-accurate approach based on the dual-time method. The numerical results are analyzed, and the computed aerodynamic coefficients of the harmonic balance method are compared with those of the dual-time method. The influence of the number of harmonics is presented. The computed Magnus force and moment coefficients are compared with the experimental data. The flow fields at different roll angles are presented. The computational efficiency of harmonic balance method is analyzed.

The results show that the aerodynamic coefficients of spinning vehicle could be predicted by the harmonic balance method with reasonable accuracy compared with the dual-time method. For the harmonic balance method, the accuracy of the computed leeward side flow is relatively poor compared with that of the computed windward side flow. Meanwhile, the computational efficiency is influenced by initial guess and the intensity of unsteady effect.

The harmonic balance method could be used for the aerodynamic prediction of spinning vehicle, which may improve the efficiency of vehicle design.

This paper presents the results of the harmonic balance method for simulating the aerodynamic characteristics of finned spinning vehicle. The accuracy and efficiency of the method are analyzed.

Drawing on benign violation theory (BVT), this paper aimed to investigate the underlining mechanism and boundary condition of the relationship between follower perception of leader failed humor and follower advice seeking.

A three-wave survey with 256 leader-follower dyads and an online experiment with 117 participants were conducted to test the hypotheses.

The results showed that leader failed humor decreased follower liking toward leader and subsequently reduced follower advice seeking. Moreover, this negative relationship was exacerbated when leader and follower had infrequent interaction.

Existing research has encouraged leaders to use humor to build and maintain successful interpersonal relationships. However, the situation that a leader may fail when attempting to present humor is neglected. This study advances the concept of leader failed humor and explores its subsequent consequences.

This paper aims to explore generational effects on work‐family conflict and synergy

The design is cross‐sectional and investigates large US national probability samples. Multiple regressions and ANOVAs were used in the analyses.

Generational differences in work‐family conflict and synergy were found. Mental health and job pressure were the strongest predictors of work‐family conflict for each group. Matures were significantly more satisfied than baby boomers and generation Xers.

All measures were self‐reports collected at one point in time. Thus, common method variance may be an issue and causal inferences cannot be made. Life stage and family stage differed for the generational groups and this should be explored in subsequent research.

Managers and human resource professionals need to consider generational differences in work‐family program design and monitor patterns of program usage for each group. Generation X members are particularly concerned about work/life balance.

This is the first paper to investigate generational issues affecting work‐family conflict and synergy. The findings are particularly relevant to managers and human resource professionals.

Nanofluids are widely used in heat transfer phenomena owing to the higher rate of heat removal as compared to their base fluids. Nanoparticle’s motion in nanofluids is analysed by slip mechanisms that consider physical properties, which can be found in literature. It is assumed that among few, only Brownian motion and thermophoresis affect the slip mechanism to produce a relative velocity between the nanoparticles and the base fluid. The purpose of this paper is to study the effects of Brownian motion and thermophoresis in a square cavity by considering it pure fluid as well as porous cavity.

A finite element method is used to solve the flow porous equations together with the heat transfer equation and the mass transfer equation numerically. The heat and mass transfer equations were modified to take into consideration the Brownian motion as well as the thermophoresis effect.

A negligible amount of Brownian motion and thermophoresis effect has been found by considering 1 to 3 Vol.% of aluminium oxide as nanoparticles suspended in base fluid of water.

This study has provided an interesting insight into the importance of Brownian motion as well as the thermophoresis effect in heat enhancement.

The present study is believed to be an interesting and original contribution on nanofluid thermal behaviours.

Under this heading are published regularly abstracts of all Reports and Memoranda of the Aeronautical Research Committee, Reports and Technical Notes of the U.S. National Advisory Committee for Aeronautics, and publications of other similar research bodies as issued

This publication is a record of a systematic study by records of pressure as a function of time of the cooling effect of the walls of a closed metal vessel in which the explosion of a mixture of air and hydrocarbons is obtained by an electric spark.

The purpose of this paper is to do a comprehensive study on the unsteady general three-dimensional stagnation-point flow and heat transfer of a nanofluid by Buongiorno’s model.

In this study, the convective transport equations include the effects of Brownian motion and thermophoresis. By introducing new similarity transformations for velocity, temperature and nanoparticle volume fraction, the basic equations governing the flow, heat and mass transfer are reduced into highly non-linear ordinary differential equations. The resulting non-linear system has been solved both analytically and numerically.

The analysis shows that velocity, temperature and nanoparticle concentration profiles in the respective boundary layers depend on five parameters, namely unsteadiness parameter A, Brownian motion parameter Nb, thermophoresis parameter Nt, Prandtl number Pr and Lewis number Le. It is found that the thermal boundary layer thickens with a rise in both of the Brownian motion and the thermophoresis effects. Therefore, similar to the earlier reported results, the Nusselt number decreases as the Brownian motion and thermophoresis effects become stronger. A correlation for the Nusselt number has been developed based on a regression analysis of the data. This correlation predicts the numerical results with a maximum error of 9 percent for a usual domain of the physical parameters.

The stagnation point flow toward a wavy cylinder (with nodal and saddle stagnation points) that a little attention has been given to it up to now. The examination of unsteadiness effect on the general three-dimensional stagnation-point flow. The application of an interesting and global model (Boungiorno’s model) for the nanofluid that incorporates the effects of Brownian motion and thermophoresis. The study of the effects of Brownian motion and thermophoresis on the nanofluid flow, heat and mass transfer characteristics. The prediction of correlation for the Nusselt number based on a regression analysis of the data. General speaking, we can tell the problem with this geometry, characteristics, the applied model, and comprehensive results, was Not studied and analyzed in literature up to now.

The purpose of this paper is to study natural convection heat transfer and fluid flow in a square cavity filled with CuO-water nanofluid.

The entire length of the bottom wall of the cavity is covered by two pairs of heat source-sink, whereas the other walls are insulated. The governing equations of fluid flow are discretized using a finite volume method with a collocated grid arrangement. The coupling between velocity and pressure is solved using the SIMPLEC and the Rhie and Chow interpolation is used to avoid the checker-board solutions for the pressure.

The numerical results are reported for the effect of Rayleigh number, solid volume fraction and both presence and absence of thermophoresis and Brownian motion effects. The numerical results show an improvement in heat transfer rate for the whole range of Rayleigh numbers when Brownian and thermophoresis effects are considered. Furthermore, an increase in the Rayleigh number and nanoparticle volume fraction in both cases – when Brownian and thermophoresis effects are neglected or considered – has an excellent influence on heat transfer of nanofluids.

The area of nanofluids is very original.