Effects of stretching/shrinking on the thermal performance of a fully wetted convective-radiative longitudinal fin of exponential profile

The present investigation focuses on the thermal performance of a fully wet stretching/shrinking longitudinal fin of exponential profile coated with a mechanism like a conveyer belt.The modeled equation is non-dimensionalized and solved by applying the Runge-Kutta-Fehlberg(RKF)method.The effects of parameters such as the wet parameter,the fin shape parameter,and the stretching/shrinking parameter on the heat transfer and thermal characteristics of the fin are graphically analyzed and discussed.It is inferred that the negative effects of motion and internal heat generation on the fin heat transfer rate can be lessened by setting a shrinking mechanism on the fin surface.The current examination is inclined towards practical applications and is beneficial to the design of fins.

Convective heat and mass transfer effects in three-dimensional flow of Maxwell fluid over a stretching surface with heat source

Heat and mass transfer effects in three-dimensional flow of Maxwell fluid over a stretching surface were addressed.Analysis was performed in the presence of internal heat generation/absorption. Concentration and thermal buoyancy effects were accounted. Convective boundary conditions for heat and mass transfer analysis were explored. Series solutions of the resulting problem were developed. Effects of mixed convection, internal heat generation/absorption parameter and Biot numbers on the dimensionless velocity, temperature and concentration distributions were illustrated graphically. Numerical values of local Nusselt and Sherwood numbers were obtained and analyzed for all the physical parameters. It is found that both thermal and concentration boundary layer thicknesses are decreasing functions of stretching ratio. Variations of mixed convection parameter and concentration buoyancy parameter on the velocity profiles and associated boundary layer thicknesses are enhanced. Velocity profiles and temperature increase in the case of internal heat generation while they reduce for heat absorption. Heat transfer Biot number increases the thermal boundary layer thickness and temperature. Also concentration and its associated boundary layer are enhanced with an increase in mass transfer Biot number. The local Nusselt and Sherwood numbers have quite similar behaviors for increasing values of mixed convection parameter, concentration buoyancy parameter and Deborah number.

Financial frictions and the cash flow – external financing sensitivity: evidence from a panel of Pakistani firms

This paper uses a large panel of Pakistani non-financial firms over the period 2000-2013 to examine the role of financial constraints in establishing the relationship between cash flow and external financing.The results reveal that there exists a negative and significant relationship between external financing and cash flow.The finding of the substitutionary relation between internal funds availability and external financing has been viewed as evidence supporting the pecking order theory of capital structure.Yet,we show that this negative relationship is weak in case of financially constrained firms.We also analyze how credit multiplier affects external financing decisions of financially constrained and unconstrained firms.The results show that for financially unconstrained firms,the negative sensitively of external financing increases with asset tangibility.However,for financially constrained firms,the negative sensitivity of external financing to cash flow either decreases or turns positive as the tangibility of assets increases.This finding implies that financially constrained firms benefit more from investing in tangible assets because such assets not only help relax financial constraints but also having a potential to be a direct source of funds in periods of negative cash flow shocks.

A Study on the Effects of Internal Heat Generation on the Thermal Performance of Solid and Porous Fins using Differential Transformation Method

In this study,the impacts of internal heat generation on heat transfer enhancement of porous fin is theoretical investigated using differential transform method.The parametric studies reveal that porosity enhances the fin heat dissipating capacity but the internal heat generation decreases the heat enhancement capacity of extended surface.Also,it is established that when the internal heat parameter increases to some certain values,some negative effects are recorded where the fin stores heat rather than dissipating it.This scenario defeats the prime purpose of the cooling fin.Additionally,it is established in the present study that the limiting value of porosity parameter for thermal stability for the passive device increases as internal heat parameter increases.This shows that although the internal heat parameter can help assist higher range and value of thermal stability of the fin,it produces negative effect which greatly defeats the ultimate purpose of the fin.The results in the work will help in fin design for industrial applications where internal heat generation is involved.

EXPERIMENTAL RESEARCH ON INTERNAL WAVES GENERATED BY A MOVING BODY IN A STRATIFIED FLUID

Two-dimensional internal waves generated by a moving flat body in a continuous- ly stratified fluid are investigated by using three kinds of flow-visualization methods:electrolytic precipitation,hydrogen bubbles,and dye streaks.Attentions are paid mainly to the generation and propagation process in the upstream region under low internal Froude number(1/10π<F_r<1/2π).The features of the upstream disturbances as well as their relationship with stratification number K (K=1/F_r) are illustrated.The corresponding theoretical analysis is briefly presented,and by comparison,the experimental and theoretical results agree well.

Large-eddy simulation of the generation and propagation of internal solitary waves

A modified large-eddy simulation model,the dynamic coherent eddy model(DCEM)is employed to simulate the generation and propagation of internal solitary waves(ISWs)of both depression and elevation type,with wave amplitudes ranging from small,medium to large scales.The simulation results agree well with the existing experimental data.The generation process of ISWs is successfully captured by the DCEM method.Shear instabilities and diapycnal mixing in the initial wave generation phase are observed.The dissipation rate is not equal at different locations of an ISW.ISW-induced velocity field is analyzed in the present study.The structure of the bottom boundary layer(BBL)of internal wave packets is found to be different from that of a single ISW.A reverse boundary jet instead of a separation bubble exists behind the leading internal wave while separation bubbles appear in other parts of the wave-induced velocity field.The boundary jet flow resulting from the adverse pressure gradients has distinctive dynamics compared with free shear jets.

Unique Outcomes of Internal Heat Generation and Thermal Deposition on Viscous Dissipative Transport of Viscoplastic Fluid over a Riga-Plate

Boundary layer stagnation point flow of Casson fluid over a Riga plate of variable thickness is investigated in present article. Riga plate is an electromagnetic actuator consists of enduring magnets and gyrated aligned array of alternating electrodes mounted on a plane surface. Physical problem is modeled and simplified under appropriate transformations. Effects of thermal radiation and viscous dissipation are incorporated. These differential equations are solved by Keller Box Scheme using MATLAB. Comparison is given with shooting techniques along with RangeKutta Fehlberg method of order 5. Graphical and tabulated analysis is drawn. The results reveal that Eckert number,radiation and fluid parameters enhance temperature whereas they contribute in lowering rate of heat transfer. The numerical outcomes of present analysis depicts that Keller Box Method is capable and consistent to solve proposed nonlinear problem with high accuracy.

Numerical solution of micropolar fluid flow via stretchable surface with chemical reaction and melting heat transfer using Keller-Box method

The main theme of this research is to find the numerical results of stagnation point flow of micropolar fluid over a porous stretchable surface due to the physical effects of internal heat generation/absorption,melting heat transfer and chemical reaction via Keller-Box method(KBM).The graphs and tables are depicted and explained for various embedded parameters.The range of melting heat transfer parameter is 0≤M≤3,the range of chemical reaction parameter is 0≤K_(r)≤1 whereas the values of space-temperature dependent heat source/sink parameters lies in-0:4≤Q≤0:4 and-2≤Q*≤2.The upshots of the current problem illustrate that at fluid-solid interface,rate of HMT(heat and mass transfer)declined on escalating the values of stretching parameter.Moreover,as the values of internal heat source/sink parameter increases,heat transfer rate declines at fluid-solid interface.

Thermodynamic analysis for a third grade fluid through a vertical channel with internal heat generation

This paper makes the thermodynamic analysis in forced convective flow of a third grade fluid through a vertical channel. Due to the reactive nature of the fluid, the effect of internal heat generation is considered and assumed to be a linear function of temperature. The coupled nonlinear dimensionless ordinary differential equations governing the fluid flow are solved by using the Adomian decomposition method（ADM）. The effects of various physical parameters such as third grade material parameter, buoyancy parameter and heat generation parameter on the thermal structure of flow are presented and discussed.

Internet Resources and Organizational Knowledge Creation:Role of Environmental Dynamism

The development of the Internet has provided firms with the ideal opportunity to make up for the knowledge gap for achieving internal knowledge generation(IKG)and external knowledge acquisition(EKA).It is worth exploring how Internet resources can be used to satisfy organizational knowledge needs efficiently to adapt to dynamic environments.Thus,according to the resource-based view,knowledge-based view,and contingency theory,we study the impact of different types of Internet resources on the two modes of knowledge creation(IKG and EKA),as well as the moderating effect of environmental dynamism(ED)on this relationship.The hypothesized relationships were tested using the hierarchical regression analysis method with survey data collected from 399 Chinese firms.We found that Internet relationship resource and Internet human resource can simultaneously facilitate IKG and EKA,while Internet infrastructure resource positively affects IKG but has no significant impact on EKA.Furthermore,ED positively moderates the relationship between Internet relationship resource and IKG and EKA,but negatively moderates the relationship between Internet human resource and EKA.

Natural convective flow of a magneto-micropolar fluid along a vertical plate

This paper presents a numerical study of natural convective flow of an electrically conducting viscous micropolar fluid past a vertical plate. Internal heat generation (IHG) versus without IHG in the medium are discussed in the context of corresponding similarity solutions. Results are presented in terms of velocity, angular velocity, temperature, skin friction in tabular forms, local wall-coupled stress, and Nusselt number. Computations have been accomplished by parametrizing the micropolar, micro-rotation, magnetic field, suction parameters, and the Prandtl number. Several critical issues are addressed at the end of the paper with reference to a previous study by El-Hakiem. The study is relevant to high-temperature electromagnetic materials fabrication systems.

Effect of asymmetrical wall heat flux and wall temperature ratio on mixed convection in a vertical micro-porous-channel with internal heat generation

Mixed convective heat transfer in a vertical parallel plate micro-porous channel with internal heat generation and viscous dissipation,varying wall heat flux ratio and wall tem­perature ratio at the boundaries is investigated using the Darcy-Brinkman model under local thermal non-equilibrium assumption.Numerical solution for both fluid and solid temperature distributions are obtained by applying the finite element method.The effect of pertinent param­eters such as Brinkman number,Rayleigh number,Darcy number,inter-phase heat transfer co­efficient,porosity scaled thermal conductivity ratio and solid internal heat generation are discussed.The results indicate that the Nusselt number increases with the increase in the solid internal heat generation as well as Rayleigh number in both wall heat flux ratio and wall tem­perature ratio boundary conditions.It is observed that with the quantitative increase in viscous dissipation parameter Br,Nusselt number Nu increases in the presence of internal heat gener­ation and it decreases in the absence of internal heat generation,for a specific range of values of wall heat flux ratio and wall temperature ratio.Beyond this range Nu increases with the increase in Dr regardless of internal heat generation.For the cases,constant wall temperature and wall heat flux ratios,good correlation is observed in the results obtained with that of available in the literature.