The magnetohydrodynamic (MHD) flow of Casson nanofluid has several applications in engineering and medical processes. The present research work is performed to examine the unsteady viscous dissipative and radiative flow of a Casson nanofluid over a stretching sheet under the influence of a transverse magnetic field with a view to highlight the impact of Hall current. The mathematical model comprising of nonlinear coupled PDE is transformed into a set of coupled ODEs using appropriate similarity transformation. The reduced mathematical model in a similar form is then solved by adopting the successive linearization method (SLM). The residual analysis is used to validate the solutions. A parametric study is performed to inquire about the impacts of Hall current, nonlinear thermal radiation, viscous dissipation, and other pertinent flow parameters such as temperature ratio, Brownian movement, thermophoresis on the nanofluid velocities, temperature, and concentration. The effects of pertinent flow parameters are also examined on the skin-friction coefficients, Nusselt number, and Sherwood number. A quadratic regression analysis is presented to estimate the skin-friction coefficient and Nusselt number for different values of effecting parameters. Results reveal that the increasing values of Casson parameter decrease the fluid velocity and temperature, whereas a converse trend is detected in concentration profile, rate of heat transfer and mass transfer.
Construction of highways involves huge investment. These infrastructural facilities should not be allowed to deteriorate as is the case with the developing countries for want of budgetary resources. Road users commit a relatively large sum in vehicle operating costs in respect of poorly maintained roads. This wasteful expenditure could be better channelled by levying a moderate highway maintenance toll to generate sufficient revenue to keep the main road networks well maintained. This will induce private entrepreneurs to take up the maintenance responsibilities efficiently and will free the limited budgetary resources to take care of constructional liabilities. The paper advocates this concept by considering some relevant aspects like economic principles, road users costs, tolling potential, possibilities and problems etc. Hypocrisies associated with the free roads concept are further exposed. The illustrations, wherever necessary, are from India which has critical maintenance problems in respect of its large network of roads. The paper finally recommends setting up of a separate self-financed maintenance organisation dealing exclusively with maintenance of roads and bridges. (A)
The paper attempts to present a methodology to evaluate the potential toll-viability of bypasses and similar other facilities like expressways having an alternative route. Toll viability of such projects cannot be decided by merely evaluating the benefits accruing due to new facility. Congestion and inter-mixing of fast moving through traffic with slow moving local traffic are the basic problems in respect of by-passes to be tackled through restrictive congestion toll as a traffic management measure. Methodology presented attempts this by suitably dovetailing the principles of normal and congestion tolls. It is mainly based on 'trip-time' concept. Trip-time curves have been developed using the speed-flow equations of RUCS 1982. Use of diversion curves to develop demand curves and monetary value of time savings are other concepts used. The paper attempts to present the methodology as one possible method and to this extent it is basically indicative in nature. Perfection and strict accuracy is neither intended nor rigorously attempted, but it will automatically follow once accurate data base is used. The methodology provides a simple and quick means to appraise toll-based facilities like by-passes or expressway even though it is primarily developed in respect of bypasses only. (A)
The phenomenon of heat transfer is prevalent in industries and has an extensive range of applications. However, mostly the discussion of heat transfer problems is limited to the study of the first law of thermodynamics, which deals with energy conservation. It is just restricted to the quantity of energy, not to its quality; i.e., there is no difference between the work (high‐grade energy) and the heat (low‐grade energy). A measurement of the degree of randomness of energy in a system is known as entropy. It is unavailable for doing useful work because work takes place only from ordered molecular motion. Even though many boundary layer models exist in the literature to investigate the flow and heat transfer of various fluids along a stretching surface, they have not yet been used at their maximum ability. The main motive of the current research is to discuss entropy generation or its minimization during heat transfer. This work presents an entropy generation analysis for the transient three‐dimensional stagnation point flow of a hydromagnetic Casson fluid flowing over a stretching surface in the existence of Hall current, viscous dissipation, and nonlinear radiation. The physical configuration of the present work is described in terms of partial differential equations (PDEs) of nonlinear nature. Furthermore, these PDEs are converted into ordinary differential equations by using some relevant similarity transformations. An efficient numerical method named as the spectral quasilinearization method (SQLM) is used to solve this model. The expression of the Bejan number and volumetric entropy generation rate is also computed. A parametric analysis, including the essential physical parameters, is performed to examine the influences of distinct flow parameters on the velocity profile, temperature profile, Bejan number, entropy generation number, and the coefficients of skin friction and the Nusselt number. In order to further insight into the emerging physical quantities of engineering interest, multiple quadratic regression models are used to estimate the coefficients of skin friction and heat transfer.
India has the second largest road network in the world. Bulk of this road network, comprising major district roads, rural roads and urban roads constitute about 3.14 million km out of a total network of 3.34 million km. The traffic on these roads (excluding NH and State highways) mostly comprises two wheelers, three wheelers and slow moving vehicles that do not have any significant laden weight. Concrete pavements with smaller thickness/panel size can be conveniently constructed at such locations. IRC has recently published a number of codes/documents to meet such demand. This paper attempts to suggest as to how concrete roads can spread their wings wider to cover urban roads, rural roads and MDRs instead of concentrating only on National and State Highways. This will provide a long lasting and cost-effective remedy to the existing poor condition of these roads. Concrete is a better material to withstand hot climate and high rainfall areas. This characteristic should effectively be used to construct concrete roads, as long lasting pavements across the entire road network.
The paper attempts to suggest the appropriate system and philosophy for highway toll in the context of a developing country. This is done by broadly demonstrating the existing potential of toll viability in respect of some major projects of India. India has been assumed to typically represent the problems of developing countries. The case of emergent need for toll revenue in the context of a developing country has been established by illustrations from the Indian context showing how critical crossings and road improvement projects which could have been constructed out of toll revenue have been deferred due to inadequate budgetary resource position. The probable strategies that can possibly be adopted have then been discussed. The paper further uses the management concepts and elaborates broadly about the relevant planning, financing and administrative system that could possibly be adopted for levying highway tolls on a broad basis in developing countries. This, it is felt, will make the concept of highway tolls meaningful, ensuring badly warranted speedy highway development. (A)
In the current analysis, we analyze the steady magnetohydrodynamic (MHD) micropolar nanofluid stagnation point flow adjacent to a stretching surface. The heat transfer characteristics within the flow field are influenced by radiative as well as dissipa- tive effects. The mathematical model consists of coupled partial differential equations which are transformed into similarity form by implementing similarity transformation. The spectral method based linearization technique, known as successive linearization technique, is utilized to obtain a numerical solution of the governing equations. The profiles of velocity, concentration, angular ve- locity, and temperature are obtained and discussed for their variation with respect to the non-dimensional flow parameters such as magnetic parameter, material parameter, and radiation parameter. Regression analysis is also performed on local Nusselt number, and it suggests that the effect of Eckert number is dominant on local Nusselt number in comparison to radiation parameter.
'%3e%3ccircle r='20' fill='%23008'/%3e%3ccircle r='17.5' fill='%23fff'/%3e%3ccircle r='3.5' fill='%23008'/%3e%3cg id='d'%3e%3cg id='c'%3e%3cg id='b'%3e%3cg id='a' fill='%23008'%3e%3ccircle r='.875' transform='rotate(7.5 -8.75 133.5)'/%3e%3cpath d='M0 17.5.6 7 0 2l-.6 5L0 17.5z'/%3e%3c/g%3e%3cuse xlink:href='%23a' transform='rotate(15)'/%3e%3c/g%3e%3cuse xlink:href='%23b' transform='rotate(30)'/%3e%3c/g%3e%3cuse xlink:href='%23c' transform='rotate(60)'/%3e%3c/g%3e%3cuse xlink:href='%23d' transform='rotate(120)'/%3e%3cuse xlink:href='%23d' transform='rotate(-120)'/%3e%3c/g%3e%3c/svg%3e)
'%3e%3cpath fill='%23001489' d='M0 0v6h9V0z'/%3e%3cpath fill='%23e03c31' d='M0 0v3h9V0z'/%3e%3cg stroke='%23fff' stroke-width='2'%3e%3cpath id='d' d='m0 0 4.5 3L0 6m4.5-3H9'/%3e%3cuse xlink:href='%23b' stroke='%23ffb81c' clip-path='url(%23c)'/%3e%3c/g%3e%3cuse xlink:href='%23d' fill='none' stroke='%23007749' stroke-width='1.2'/%3e%3c/g%3e%3c/svg%3e)