• Ram Prakash

      Articles written in Pramana – Journal of Physics

    • Performance evaluation of self-breakdown-based single-gap plasma cathode electron gun

      Niraj Kumar Nalini Pareek Udit Narayan Pal Deepak Kumar Verma Jitendra Prajapati Mahesh Kumar Bharat Lal Meena Ram Prakash

      More Details Abstract Fulltext PDF

      This paper presents the experimental studies on self-breakdown-based single-gap plasma cathode electron (PCE) gun (5–20 kV/50–160 A) in argon, gas atmosphere and its performance evaluation based on particle-in-cell (PIC) simulation code `OOPIC-Pro’.The PCE-Gun works in conducting phase (low energy, high current) of pseudospark discharge. It produces an intense electron beam, which can propagate more than 200 mm in the drift space region without external magnetic field. The profile of this beam in the drift space region at different breakdown conditions (i.e., gas pressures and applied voltages) has been studied and the experimental results are compared with simulated values. It is demonstrated that ∼30% beam current is lost during the propagation possibly due to space charge neutralization and collisions with neutral particles and walls.

    • Combined effects of free convection and chemical reaction with heat–mass flux conditions: A semianalytical technique


      More Details Abstract Fulltext PDF

      This paper discusses the effect of heat and mass flux on the natural convective laminar flow of a viscous incompressible fluid under the influence of radiation, magnetic field and Joule heating. The partial differentialequations related to the problem have been changed as a set of ordinary differential equations employing non-dimensional quantities. Semianalytical approach such as the Adomian decomposition method (ADM) is employedto solve the system of ordinary differential equations. The behaviour of characterising parameters on the velocity, heat and mass transfer profiles, and the engineering quantities of interest, i.e. skin friction, heat and mass transfer rates and other indices are presented through graphs

    • Hybrid nanofluid MHD motion towards an exponentially stretching/shrinking sheet with the effect of thermal radiation, heat source and viscous dissipation


      More Details Abstract Fulltext PDF

      In this article, the heat transfer of Al$_2$O$_3$–Cu/H$_2$O in the magnetohydrodynamic (MHD) stagnation point flow in the direction of an exponentially stretching/shrinking sheet with the effect of heat source, thermal radiation and viscous dissipation is examined. The inclusion of dissipative heat, thermal radiation and additional heat source enriches the study as well. Using suitable similarity transformations, the governing partial differential equations are transformed into ordinary differential equations (ODEs). The ODEs are solved numerically by the built-in function bvp4c in MATLAB. By the addition of nanoparticle, effects of various parameters were studied, and the outcomes revealed that the skin friction coefficient decreases and the local Nusselt number increases. In comparison, viscous dissipation causes an improvement in the fluid thermal state and, as a result, triggers the thermal boundary layer to rise.

  • Pramana – Journal of Physics | News

    • Editorial Note on Continuous Article Publication

      Posted on July 25, 2019

      Click here for Editorial Note on CAP Mode

© 2023-2024 Indian Academy of Sciences, Bengaluru.