Mohan Jagadeesh Kumar | VIT University (original) (raw)

Papers by Mohan Jagadeesh Kumar

Analytical expressions were obtained for temperature profiles, energy generated due to viscous di... more Analytical expressions were obtained for temperature
profiles, energy generated due to viscous dissipation and
energy gained by fluids for fully developed laminar flow
through three different duct configurations. The walls of the
duct were insulated, and viscous dissipation included. The
unknown temperature at the wall (that appears owing to the
boundary conditions being Neumann type) was evaluated by
equating the energy generated by viscous dissipation to the
energy gained by the fluid

This paper presents the effects of aerodynamic drag reduction devices on a heavy truck-trailer. A... more This paper presents the effects of aerodynamic drag reduction devices on a heavy truck-trailer. Aerodynamic analysis including the assessment of fuel economy for both basic and modified truck-trailer profile was carried out numerically by using ANSYS FLUENTsoftware. It was found that modifications to the basic truck-trailer reducedaerodynamic drag by 21 % and improved fuel savings up to 15 % without making any negative impact on its stability. The effect of protruded profile such as external rear view mirror on aerodynamics of truck-trailer was also analyzed

Steady laminar forced convection heat transfer in the thermal entrance region of concentric annul... more Steady laminar forced convection heat transfer in the thermal entrance region of concentric
annuli has been studied considering viscous dissipation characterized by the Brinkman
number. The inner and outer pipes have been kept at constant and equal
temperature. Two cases of entry temperatures have been considered, case 1: an entry
temperature that varies with the radial coordinate, obtained by an adiabatically prepared
fluid, i.e., attained by the fluid due to viscous dissipation in an adiabatic concentric annular
duct and case 2: the conventional uniform entry temperature. The numerical results
presented include the nondimensional temperature profiles, Nusselt numbers, and heat
transferred from (or to) the inner and outer pipes. It has been shown from the numerical
solutions that it is necessary to employ the dissipative entry temperature in place of conventional
uniform entry temperature for higher Brinkman numbers. The results for circular
pipes follow when the radius ratio takes the limiting value of zero.

In this paper, heat transfer analysis for an air-air heat exchanger was experimentally carried ou... more In this paper, heat transfer analysis for an air-air heat exchanger was experimentally carried out to find its thermal performance and effectiveness. Air-air heat exchanger equipped with finned heat pipes was considered for the experimentation. Mass flow rate of air was considered in between 0.24 to 0.53 kg/s. The temperature at the condenser side of the heat pipe heat exchanger was kept constant at around 23 °C and at the evaporator part it was varied from 88 to 147 °C. The performance of heat pipe heat exchanger was evaluated at different mass flow rate of air, in terms of effectiveness and compared with its corresponding value found by theoretical analysis.

Analytical expressions for the Nusselt number at the inner and outer pipes, kept at unequal tempe... more Analytical expressions for the Nusselt number at the inner and outer pipes, kept at unequal temperatures, for laminar forced convection through annuli including viscous dissipation have been obtained in the conduction limit. This article examines the dependence of the limiting Nusselt numbers on Brinkman number and the degree of asymmetry in inner and outer pipe temperatures. Further, the limiting temperature profile obtained when viscous dissipation is included serves the purpose of providing the downstream boundary condition needed in solving the elliptic form of conservation of thermal energy equation that arises when axial conduction is included

Flow separation at the vehicle's rear end is the major cause of an aerodynamic drag in a car. In ... more Flow separation at the vehicle's rear end is the major cause of an aerodynamic drag in a car. In order to delay the flow separation at the rear, bump-shaped vortex generators at the roof end of a car are tested in this paper for two different types of car models Sedan and Hatchback. The aerodynamic analysis is carried out using GAMBIT and FLUENT for Sedan and Hatchback models. Vortex Generators are found to be not very sensitive for the designing parameters. CFD analysis confirms that the use of Vortex Generators reduces both the drag and lift coefficients.