The Experts below are selected from a list of 114 Experts worldwide ranked by ideXlab platform

Mete Avci - One of the best experts on this subject based on the ideXlab platform.

  • the effects of nozzle aspect ratio and nozzle number on the performance of the ranque hilsch vortex tube
    Applied Thermal Engineering, 2013
    Co-Authors: Mete Avci
    Abstract:

    Abstract An experimental study is carried out to investigate the effects of nozzle aspect ratio and nozzle number on the performance of a vortex tube. Two sets of vortex generator (a single nozzle set with aspect ratio of AR = 0.25, 0.44 and 0.69 and a multiple nozzle set with 2 and 3 nozzle number having the same Total Flow Area) are tested under different inlet pressures. Dry air is used as the working fluid. The experimental results reveal that the nozzle aspect ratio has a great effect on the energy/temperature separation mechanism. The increase in the nozzle aspect ratio leads to the larger mixing zones, which, in turn, decreases the temperature difference between the cold and hot stream, the heating and the cooling performance. The results also showed that the vortex tube with a single nozzle yields better performance than the vortex tube with 2 and 3 nozzles.

  • The effects of nozzle aspect ratio and nozzle number on the performance of the Ranque–Hilsch vortex tube
    Applied Thermal Engineering, 2013
    Co-Authors: Mete Avci
    Abstract:

    Abstract An experimental study is carried out to investigate the effects of nozzle aspect ratio and nozzle number on the performance of a vortex tube. Two sets of vortex generator (a single nozzle set with aspect ratio of AR = 0.25, 0.44 and 0.69 and a multiple nozzle set with 2 and 3 nozzle number having the same Total Flow Area) are tested under different inlet pressures. Dry air is used as the working fluid. The experimental results reveal that the nozzle aspect ratio has a great effect on the energy/temperature separation mechanism. The increase in the nozzle aspect ratio leads to the larger mixing zones, which, in turn, decreases the temperature difference between the cold and hot stream, the heating and the cooling performance. The results also showed that the vortex tube with a single nozzle yields better performance than the vortex tube with 2 and 3 nozzles.

Virendra Kumar Saharan - One of the best experts on this subject based on the ideXlab platform.

  • Degradation of reactive blue 13 using hydrodynamic cavitation: Effect of geometrical parameters and different oxidizing additives.
    Ultrasonics Sonochemistry, 2017
    Co-Authors: Sunil Rajoriya, Swapnil Bargole, Virendra Kumar Saharan
    Abstract:

    Abstract Decolorization of reactive blue 13 (RB13), a sulphonated azo dye, was investigated using hydrodynamic cavitation (HC). The aim of research article is to check the influence of geometrical parameters (Total Flow Area, the ratio of throat perimeter to its cross-sectional Area, throat shape and size, etc.) and configuration of the cavitating devices on decolorization of RB13 in aqueous solution. For this purpose, eight cavitating devices i.e. Circular and slit venturi, and six orifice plates having different Flow Area and perimeter were used in the present work. Initially, the effects of various operating parameters such as solution pH, initial dye concentration, operating inlet pressure and cavitation number on the decolorization of RB13 have been investigated, and the optimum operating conditions were found. Kinetic analysis revealed that the decolorization and mineralization of RB13 using HC followed first order reaction kinetics. Almost 47% decolorization of RB13 was achieved using only HC with slit venturi as a cavitating device at an optimum inlet pressure of 0.4 MPa and pH of the solution as 2.0. It has been found that in case of orifice plates, higher decolorization rate of 4 × 10−3 min−1 was achieved using orifice plate 2 (OP2) which is having higher Flow Area and perimeter (α = 2.28). The effect of process intensifying agents (hydrogen peroxide and ferrous sulphate) and different gaseous additives (oxygen and ozone) on the extent of decolorization of RB13 were also examined. Almost 66% decolorization of RB13 was achieved using HC combined with 2 L min−1 of oxygen and in combination with ferrous sulphate (1:3). Nearly 91% decolorization was achieved using HC combined with H2O2 at an optimum molar ratio (dye:H2O2) of 1:20 while almost complete decolorization was observed in 15 min using a combination of HC and ozone at 3 g h−1 ozone feed rate. Maximum 72% TOC was removed using HC coupled with 3 g h−1 ozone feed rate.

  • Computational study of different venturi and orifice type hydrodynamic cavitating devices
    Journal of Hydrodynamics, 2016
    Co-Authors: Virendra Kumar Saharan
    Abstract:

    This paper reports optimization of various geometrical parameters of two types of hydrodynamic cavitation reactors (HC) such as venturi type and orifice type. Mostly orifice and venturi nozzles are used as HC reactor, a simple valve can also be used to cause cavitation which depends on geometry and Area of opening. Different operating and geometrical parameters such as divergence angle, throat height/diameter to length ratio, number of holes and inlet pressure to the cavitating device were selected to study the inception, growth and dynamics of cavities. In this work, a comprehensive computational fluid dynamics simulation is performed to numerically investigate the 3-D Flow behaviors within HC reactors using cavitational model with standard k -ε Turbulence model. The study of different geometries of venturi type HC reactor (like slit, circular and elliptical) shows that 1:1 of the ratio of throat height/diameter to length and 6.5° of divergence angle is an optimum geometry for best cavitational activity. In case of orifice, 1:3 of the ratio of diameter to length is best for cavitation and an increase in the Total Flow Area increases the cavitational yield.

  • Computational study of different venturi and orifice type hydrodynamic cavitating devices
    Journal of Hydrodynamics, 2016
    Co-Authors: Kuldeep, Virendra Kumar Saharan
    Abstract:

    This paper reports optimization of various geometrical parameters of two types of hydrodynamic cavitation reactors (HC) such as venturi type and orifice type. Mostly orifice and venturi nozzles are used as HC reactor, a simple valve can also be used to cause cavitation which depends on geometry and Area of opening. Different operating and geometrical parameters such as divergence angle, throat height/diameter to length ratio, number of holes and inlet pressure to the cavitating device were selected to study the inception, growth and dynamics of cavities. In this work, a comprehensive computational fluid dynamics simulation is performed to numerically investigate the 3-D Flow behaviors within HC reactors using cavitational model with standard k-e Turbulence model. The study of different geometries of venturi type HC reactor (like slit, circular and elliptical) shows that 1:1 of the ratio of throat height/diameter to length and 6.5° of divergence angle is an optimum geometry for best cavitational activity. In case of orifice, 1:3 of the ratio of diameter to length is best for cavitation and an increase in the Total Flow Area increases the cavitational yield.

Ong Kai Sheng - One of the best experts on this subject based on the ideXlab platform.

  • PDC Bit Hydraulic and Mud Rheological Simulation to ModelPressure Drop across Bit
    2020
    Co-Authors: Ong Kai Sheng
    Abstract:

    When fluid Flow from larger into smaller diameter pipes, it experiences a drop in pressure. High pressure drop across bit is an indication of high energy loss in the hydraulic system and also a setback to ROP performance. This is inefficient and pressure pumps would have to be of bigger sizing to make up for the losses. Present form of pressure drop models are in terms of mud density, Flow rate, and Total Flow Area. No study on mud rheological parameters specifically the Yield Stress, Consistency Index, and Power Index have been done with respect to pressure drop across bit. The objective of this research is focused on the analysis of CFD simulation and to propose optimized parameters for improved ROP. Single phase Flow study of Yield Power Law mud rheology was simulated at bottom hole of horizontal section. For accuracy of simulated results, a mesh independence test was carried out to justify the validity of the simulated results. Preliminary simulation on Yield Power Law Muds showed about 50% reduction of pressure drop across bit as Flow rate increase. Parametric study on mud rheology was carried in Design of Experiment.

  • PDC Bit Hydraulic & Mud Rheological simulation to model pressure drop across Bit
    MATEC Web of Conferences, 2017
    Co-Authors: Ong Kai Sheng, Tamiru Alemu Lemma, Shazaib Ahsan
    Abstract:

    During fluid Flow from larger to smaller diameter pipes, a drop in pressure is experienced. High pressure drop across bit indicated high energy loss in the hydraulic system and also a setback to ROP performance. This is inefficient and pressure pumps would have to be of bigger sizing to make up for the losses. Present form of pressure drop models is in terms of mud density, Flow rate, and Total Flow Area. The objective of this paper is focused on the analysis of CFD simulation and to propose optimized parameters for improved ROP. Single phase Flow study of Yield Power Law mud rheology was simulated at bottom hole of horizontal section. Parametric study on mud rheology was carried using DOE. Design points of DOE were sampled mostly using Latin Hypercube Sampling and a few by Central Composite Design. It is found that Kriging Response Surface method generated the best regression model where the predicted values are closest to the observed values and has the lowest Maximum Relative Residual (0.000336%). Inlet velocity and Power Index have significant effect on pressure drop. Consistency Index showed moderate effect while Yield Stress showed small effect to pressure drop. This research has proven that pressure loss model should take into account of mud rheology. Further research can be done with PDC bit rotation and its effect on mud behaviour.

Kuldeep - One of the best experts on this subject based on the ideXlab platform.

  • Computational study of different venturi and orifice type hydrodynamic cavitating devices
    Journal of Hydrodynamics, 2016
    Co-Authors: Kuldeep, Virendra Kumar Saharan
    Abstract:

    This paper reports optimization of various geometrical parameters of two types of hydrodynamic cavitation reactors (HC) such as venturi type and orifice type. Mostly orifice and venturi nozzles are used as HC reactor, a simple valve can also be used to cause cavitation which depends on geometry and Area of opening. Different operating and geometrical parameters such as divergence angle, throat height/diameter to length ratio, number of holes and inlet pressure to the cavitating device were selected to study the inception, growth and dynamics of cavities. In this work, a comprehensive computational fluid dynamics simulation is performed to numerically investigate the 3-D Flow behaviors within HC reactors using cavitational model with standard k-e Turbulence model. The study of different geometries of venturi type HC reactor (like slit, circular and elliptical) shows that 1:1 of the ratio of throat height/diameter to length and 6.5° of divergence angle is an optimum geometry for best cavitational activity. In case of orifice, 1:3 of the ratio of diameter to length is best for cavitation and an increase in the Total Flow Area increases the cavitational yield.

Shazaib Ahsan - One of the best experts on this subject based on the ideXlab platform.

  • PDC Bit Hydraulic & Mud Rheological simulation to model pressure drop across Bit
    MATEC Web of Conferences, 2017
    Co-Authors: Ong Kai Sheng, Tamiru Alemu Lemma, Shazaib Ahsan
    Abstract:

    During fluid Flow from larger to smaller diameter pipes, a drop in pressure is experienced. High pressure drop across bit indicated high energy loss in the hydraulic system and also a setback to ROP performance. This is inefficient and pressure pumps would have to be of bigger sizing to make up for the losses. Present form of pressure drop models is in terms of mud density, Flow rate, and Total Flow Area. The objective of this paper is focused on the analysis of CFD simulation and to propose optimized parameters for improved ROP. Single phase Flow study of Yield Power Law mud rheology was simulated at bottom hole of horizontal section. Parametric study on mud rheology was carried using DOE. Design points of DOE were sampled mostly using Latin Hypercube Sampling and a few by Central Composite Design. It is found that Kriging Response Surface method generated the best regression model where the predicted values are closest to the observed values and has the lowest Maximum Relative Residual (0.000336%). Inlet velocity and Power Index have significant effect on pressure drop. Consistency Index showed moderate effect while Yield Stress showed small effect to pressure drop. This research has proven that pressure loss model should take into account of mud rheology. Further research can be done with PDC bit rotation and its effect on mud behaviour.