Search

An Energy in the form of heat, is crucial to conserve in every aspect. Air conditioning, chemical processing, thermal power plants, refrigeration equipment, etc. are only a few of the various industries that exist and are dealing with a lot of issues, including utilizing effects, reuse of heat, or conserving, etc. Thermal energy can be recovered by heat exchanger. Heat transfer devices require significant financial expenses for a variety of capital and operating expenses, as a result, it is crucial to create heat exchangers that use less energy, cost, and resources. Heat transfer improvement strategies come in a wide variety, dive into detail on two of these methods— a nanofluid insets tape insertion, and a twist tube. The factors that influencing on nanofluid's operation which improve the heat transfer system efficiency have been study, in addition, a study of the development of heat transfer utilizing twist tubes has been conducted. [ABSTRACT FROM AUTHOR]

Heat transfer scientists are all the time looking for innovative ways toward boosting an effectiveness of energy devices via heat transfer advancement. Because of its thermal performance, excellent hydrodynamic performance, low fouling thermal resistance, and good recompense in helically coiled tubes, heat exchangers have been used in the agricultural, refrigerators, metallurgical, medicinal, biochemical, electric, textiles, and petrochemical sectors. Moreover, the system has disadvantages such as low or dead flow zones around the baffles where corrosion and fouling can occur, ineffective use of shell side pressure drop, and flow induced tube vibration due to which mechanical damage can occur. Twisted tubes are employed for increase heat transfer coefficient on the heat exchangers, which aids in heat exchanger size reduction. Furthermore, nanofluids have piqued concentration of multidisciplinary researchers owing to its unique thermo-physical features and several potential benefits in heat exchanger systems. This work discusses and summarizes nanofluid synthesis, heat transfer increase employing nanofluids in heat exchanger uses, and different twisted tube heat exchangers. Furthermore, a few limitations and problems are addressed, and future research directions are described. [ABSTRACT FROM AUTHOR]

Advanced heat transfer devices in the form of different channels where artificial mass forces influence on hydrodynamics stability in low gravity area and argumentation of heat transfer is considered. Experiments are fulfilled with large variety of geometrical forms of channels (inserts in straight tubes, fluted tubes, annular channel with rotation of flow, spiral coils, twisted tubes etc.) and different heat transfer media and their vapour (liquid metals, water, cryogenic liquids). [ABSTRACT FROM AUTHOR]

The introduction of the twisted coil in this venture is to ensure the appropriate heat transfer rate generally speaking across the shell structure in light of the fact that the most extreme stream pace of the cylinder will be in its middle as there is low contact and with likewise the design of the shell variety it is difficult to equitably keep up with the heat transfer rate all around the shell. We consider that this type of twisted coil will cover the major part of the shell by twisted guiding area of the coolant. Here we have used a normal twisted coil and a twisted coil with the heat vents. In this review, the heat transfer trademark in the Twisted coil tubes is explored mathematically by utilizing ANSYS FLUENT. These investigations are completed at various coil structure. At last, the outcomes are examined exhaustively and the Performance of the Twisted coil is displayed for various varieties. [ABSTRACT FROM AUTHOR]

Shell and Tube heat exchanger with three baffles and six internal tubes is designed and fabricated. The objective of the designed heat exchanger is to heat the cold air, by the hot air supplied. The cold air is supplied by a blower and hot air is supplied by a forced convection setup for heat transfer process. The experimental setup conditions are validated with the Computational Fluid Dynamic (CFD) analysis using Ansys Fluent. Post validation, it is observed that the outlet temperatures of the experimental results are similar to the simulation results. [ABSTRACT FROM AUTHOR]

In this article, we study the Kelvin-Helmholtz (KH) instability of magnetohydrodynamic (MHD) waves propagating in the solar atmosphere. The main focus is on the modeling the KH instability development in coronal mass ejections (CMEs) and solar surges in view of its (instability) contribution to triggering a wave turbulence subsequently leading to an effective coronal heating. KH instability of MHD waves in coronal active regions recently observed and imaged in unprecedented detail in EUV thanks to the high cadence, high-resolution observations by SDO/AIA instrument, and spectroscopic observations by Hinode/EIS instrument is a challenge for modeling these events. It is shown that considering the solar mass flows of coronal mass ejections as moving cylindrical twisted magnetic flux tubes the imaged instability can be explained in terms of unstable m = -3 MHD mode. Obtained critical jet speeds for the instability onset as well as the linear wave growth rates are in good agreement with observational data. Alongside the KH instability in CMEs, we study also the conditions for the instability onset in solar surges. It is obtained that MHD high-mode harmonics propagating along such jets might become unstable against KH instability at critical jets' velocities accessible for surges. [ABSTRACT FROM AUTHOR]

Corrugation instabilities of the Riemann problem in relativistic hydrodynamics are investigated numerically in the case of nonvanishing velocities tangent to the initial discontinuity. Three dimensional simulations are performed for the ultrarelativistic and the perfect gas equations of state for moderately relativistic speeds. The results agree qualitatively for both equations of state. Shock waves and rarefaction waves behave in a stable way, and a Kelvin-Helmholtz type instability develops near the contact discontinuity. [ABSTRACT FROM AUTHOR]

Experimental investigation of heat transfer and friction characteristics was conducted on the out side of horizontal carbon steel heat transfer tubes under the pressure of saturated vapour 0.04 MP (gauge pressure). The test tubes included spiral-grooved tubes, corrugated tube and smooth tube. The use of water as test fluids has allowed to cover a wide range of turbulent fluid flow conditions: Reynolds number from 1×104 to 5×104. The heat transfer coefficients and amount of vapour condensation of spiral-grooved tube with different structure parameters are measured. The spiral-grooved tube has the best heat transfer performance compared with corrugated tube and smooth tube. The maximum heat transfer coefficients and amount of vapour condensation of spiral—groove tube is respectively 2.32 and 1.72 times as smooth tube. The maximum η of spiral groove tube as comprehensive performance evaluation is 1.86. The corrugated tube increase heat transfer coefficients only in the Reynolds numbers lower than 1.5 104, but lower than spiral—groove tube, and transfer performance is worse than smooth tube with the Reynolds numbers grow. The structure parameters influence on spiral-grooved tube performance results show that the deeper of the groove, the better heat-exchange performance with the drag coefficient increased in the same Reynolds numbers. And the greater the fin pitch and trough radius, the poorer the heat exchange effectiveness with the drag coefficient decreased. [ABSTRACT FROM AUTHOR]

The Simulator for the Linear Collider (SLIC) is a detector simulation program based on the GEANT4 toolkit. It is intended to enable end users to easily model detector concepts by providing the ability to fully describe detectors using plain text files read in by a common executable at runtime. The detector geometry, typically the most complex part of a detector simulation, is described at runtime using the Linear Collider Detector Description (LCDD). This system allows end users to create complex detector geometries in a standard XML format rather than procedural code such as C++. The LCDD system is based on the Geometry Description Markup Language (GDML) from the LHC Applications Group (LCG). The geometry system facilitates the study of different full detector design and their variations. SLIC uses the StdHep format to read input created by event generators and outputs events in the Linear Collider IO (LCIO) format. The SLIC package provides a binding to GEANT4 and many additional commands and features for the end user. © 2006 American Institute of Physics [ABSTRACT FROM AUTHOR]