حافظ حسن محمد الغزالي

The current study presents a numerical investigation of the performance for industrial cyclones using the ANSYS Fluent commercial CFD code under steady state operating conditions. investigations were conducted for model of cyclone used within the preheater system, which is one of the most important systems in the cement industry. The current study aims to verify the effect of increasing the length of vortex finder on the main performance parameters represented by the separation efficiency, pressure drop and cyclone flow velocity profile. The study also investigated the effect of fluidized boundary layers in the top wall of the cyclone as one of the most important factors affecting on the separation efficiency. The present study also added an improvement to the performance of cyclones by adding annular fins around the immersion tube (vortex finder).

Abstract— In this research paper, we practically study the effect of adding a nano-material of alpha-type aluminium oxide on the performance of the heat pipe in addition to the working fluid in the heat pipe with a volumetric mixing ratio of 5%. Through the experiment, we find that the surface temperature of the pipe increases with the increase in the heat flux applied to the heat pipe and is higher In the case of adding aluminium oxide to water, and we notice the pressure inside the tube decreases when the working fluid is a mixture of water with aluminium oxide compared to water, the deposition of alpha aluminium oxide on the screen mesh wick and deposition on the wall of the tube in the inner surface leads to a reduction in heat transfer from the evaporator to the condenser As a result, all of the above leads to an increase in thermal resistance, Efficiency decreases by between (2-40)% in case of adding al2o3 type alpha.

The natural heat transfer in ducts depend on generating an induced flow due to the difference in density between the heated fluid and it is environment. The effect of reduce cross sectional area of a vertical isothermal duct by adding half circular obstacles to the inner side of the duct. The effect of the induced flow and obstacles were study using COMSOL software and compared to heat through same duct with no flow. The results that obstacles increase induced flow by 16% compared to normal vertical duct, Also shows a reduction in value of the maximum temperature of the hot surface at the solar peak heat flux (3:00 PM).

Hydrodynamic journal bearing is one of the simplest types of bearings which faces a problem of high temperature generated with the developed industrial applications. The main goal of the present work is to carry out CFD analysis to study a thin film journal bearing supporting rotating shaft of an electric motor used to drive a cement ball mill considering thermal effect and elastic deformation. Fluid structure interaction FSI technique was used to discuss the effect of different working parameters such as journal speed and clearance ratios on the pressure distribution, temperature distribution, total deformation and the state of stresses induced in bearing. A bearing with its real dimensions has been analysed in the present wok while most previous works done for bearings with hypothetical dimensions. For this purpose, thermoelastohydro dynamic analysis for such bearing was mathematically modelled using CFD technique based on three dimensional Navier Stokes, continuity, and energy equations in fluid film and solid materials. Oil viscosity was considered as a function of pressure and temperature. The governing equations with suitable boundary conditions have been solved using ANSYS FLUENT 19. The results showed that the present CFD model was well validated with that of Amit Chauhan (2014) and the oil film temperature increases by 1% to5% while the maximum oil film pressure decreases by 30% to 50% when the journal speed increases from 490 to 1500 rpm. The bearing liner total deformation decrease by 25.3% to 47.3% when the bearing works at the same range

A numerical work supported by experimental results was carried out to studying of passing a hot solid particle on heat pipe performance. used Ansys fluent 18.0 as a computer program, geometry was published using design modular engaged in it. 3Dimention model with the steady state was studied to knowing the temperature distributed inside the evaporator and condenser part domain, more clearly to particle behavior and streamline 2Dimention model with transient was studied also. Depended on particle of 105μm diameter and experimental measuring properties set with height range (2.5 to 5) cm inside evaporator part from box, velocity with range (0.8739 to 1.377) m/s was take in consideration, the result shown enhancement in Nusselt number by (58) % when the velocity 1.377 m/s and particle bed height 5 cm compared with the first state, pressure drop with acceptable range was measured not exceed (42) %

An experimental research was carried out to study the effect of flowing a solid particle with hot air on heat pipe performance ,three heat pipes were manufactured with outer and inner diameter of (22.225 , 19.8)mm respectively , and with 1000mm long for both Evaporator , condenser and adiabatic sections were (64.5,34.5,1) cm long respectively .The three heat pipes were fixed in a wooden box and the cement fly ash was used as a bed particle cross the evaporator part with the hot air , cement fly ash properties were measured experimentally .Tests were done with air velocity range of (3.5 to 5.5)m/s and solid particle bed thickness of (2.5,5) cm , the results show that the Nusselt number was enhanced by (61.5%) for the case of 5cm particle bed thickness and (5.5) m/s air velocity with respect to the case of flow of air without solid particle . An acceptable pressure drop will happened for this case which is not exceed (39%).

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