In this study, the separation of silica particles was investigated experimentally and numerically using a CYCLONE separator. Computational Fluid Dynamics (CFD) simulation was performed using a multi-phase Eulerian-Eulerian model for air-silica powder and k-ε turbulent model. In the experiments, the effects of operating parameters including silica particle size, airflow rate, and rotational speed on CYCLONE efficiency were examined. The results showed that by increasing the particle size, the flow rate, and the body speed, the CYCLONE efficiency enhances. Furthermore, body rotation in the opposite direction of the inlet flow decreases CYCLONE efficiency by around 48% and increasing the flow rate and rotation speed increases tangential velocity, resulting in increased centrifugal force and improved CYCLONE efficiency. The experimental and simulation performance maximums are about 97 percent and 90 percent, respectively. At a constant flow rate and particle size, a 1900 rpm rotating speed of the current direction of inlet flow increases performance by approximately 10-13 percent compared to a stationary body.

Sensitivity of numerical models in the prediction of Tropical CYCLONE (TC) characteristics has been considered in numerous research studies. In this research, application of five cumulus schemes of HWRF (Hurricane Weather Research and Forecasting) model, including KF, SAS, BMJ, TiedTKE and SASAS has been examined during Tropical CYCLONE Gonu (TCG) from 4 to 7 June 2007. The simulations have been conducted using three nests with 27, 9 and 3 km resolutions. To this aim, the performance of schemes in predicting TCG intensity using minimum surface pressure and maximum 10-m wind speed are analyzed. Following, their effect on forecasting the radius of maximum wind is evaluated. The parameters of lower-level divergence, upper-level convergence, potential temperature, potential vorticity, Convective Available Potential Energy (CAPE), wind vector (both horizontal and vertical components), wind shear, precipitation and radar reflectivity have been analyzed. The results of the simulations have been compared with the analysis data, IMD and TRMM observational data and routine atmospheric parameter measured at the Chabahar station. The comparison was done in different time of TCG lifetime. To examine the performance of HWRF cumulus schemes for track and intensity of the TCG, the whole life cycle of TCG was considered. To test the efficiency of HWRF cumulus schemes in predicting some dynamical and thermodynamical parameters, the time of maximum intensity of TCG (18 UTC on 4 June 2007) was focused on. To evaluate the functionality of HWRF cumulus schemes in the coastal area, the outputs were discussed in the last two days of the TCG life cycle. Results showed that based on the used configuration, none of the five cumulus schemes predicted the TCG reaching the southern coast of Iran. Moreover, neither the pressure decrease nore the maximum wind speed were predicted accurately at the time of maximum intensity of TCG. Until TCG intensity was more that category-3, neither minimum surface pressure trend and nor the maximum wind speed trend have been forecasted well. However, for the less intense conditions, two schemes of TiedTKE and SAS produced the nearest values. The performance of all five cumulus schemes, similarly predicted the radius of the maximum wind, except TiedTKE scheme that predicted the super CYCLONE 6 hours earlier. The analysed and simulated of the vertical cross sections of potential temperature and horizontal wind were similar, respectively. The simulated values of the vertical component of wind were considerably larger than those from the analysis data and were also closer to the TCG center. The maximum values of simulated CAPE were off the Oman coast compared to the analysis values. Only the simulations using SASAS cumulus schemes showed the strongest potential vorticity near the surface. The simulated updrafts and downdrafts were larger than those from the analysis data. The simulated values of the major updrafts and downdrafts were closer to the center of the TCG, comparing to those from the analysis data. The upper-level divergence patterns were seen in both simulations using all 5 cumulus schemes and also in the analysis data, while the lower-level convergences were not captured neither in the simulations nor in the analysis data. The maximum value of the simulated accumulated precipitation using all 5 cumulus schemes were 80 mm in a 6 hour interval, however, the observational value from the TRMM was 25 mm/h. The predicted radar reflectivity from the simulations were similar and the simulated maximum values were the same, but the expansions of the simulated maximum values were different. All cumulus schemes predicted the wind shear values less than the analytical values. At Chabahar station, the observational values of the 10-m wind speed, sea level pressure, and temperature have been compared to the simulated values using all 5 cumulus schemes, in the period of 6-7 Jun 2007. The statistical parameters of correlation, standard deviation and root mean square were used to identify the best cumulus scheme. The least error prediction was obtained using KF cumulus schemes to predict the 10-m wind, the TiedTKE cumulus scheme to simulate sea level pressure the observed, and SASAS cumulus schemes to produce temperature.

The coast of Bangladesh has a specialty in terms of high bending and many offshore islands. Incorporation of the coastline and island boundaries properly in the numerical scheme is essential for accurate estimation of water levels due to surge. For that purpose a numerical scheme consisting of very fine mesh is required along the coastal belt, whereas this is unnecessary away from the coast. In this study, a fine mesh scheme covering the coastal belt and islands has been nested into a coarse mesh scheme covering up to 15 N latitude in the Bay of Bengal. For the existence of so many small and big islands and also for high bending of the coastline along the Meghna estuary, a very fine mesh scheme for the region between Barisal and Chittagong is again nested into the fine mesh scheme. A vertically integrated model is developed in Cartesian coordinate system to solve the shallow water equations using semiimplicit finite difference technique for computing surge associated with storms. The developed system is applied on a severe cyclonic storm 'SIDR' that hit Bangladesh on 15th November, 2007. The computed water levels are found to be in good agreement with those observed.

The measure of volumetric flow rate is utilized to calculate sampling volume and airborne concentration in integrated air sampling. Consequently, calibration of the sampling train to verify volumetric flow rate is critical. The relation between sampler pressure drop and volumetric flow rate was studied in support of using the former rather than the latter for the calibration of sampling trains. Four types of respirable CYCLONEs, two filter brands with membrane samples of the same and different lots of production, and two personal pump types were considered as components of the sampling trains under consideration. Volumetric flow rate and pressure drop were measured under controlled conditions in a cylindrical jar designed for these determinations. For all the configurations considered, the relation between sampler pressure drop and standard volumetric flow rate was linear. Intra-sample selection of CYCLONEs of the same type and pump type did not create significant differences in sampler pressure drop. Filter selection, regardless of brand or production lot, did create linear response functions that had statistically different slopes and intercepts. When grouped by CYCLONE type and filter brand, the sampler pressure drop at the flow rate recommended by the CYCLONE’ s manufacturers showed variability that was not normally distributed. The recommended central tendency estimate of pressure drop is the median value, with point estimates that should be specific to a CYCLONE type / filter brand combination.

The hydroCYCLONE has a very important roll in industrial separation. The consideration of its behavior is very important for design. In this investigation, behavior of water flow and particles trajectory inside a hydroCYCLONE has been considered by means of numerical and experimental methods, and results have been compared together. To have a numerical simulation, a CFD software was used, and for modeling flow the RNG k-e model applied. Finally, the effect of particle size on hydroCYCLONE performance has been studied. It was found that the grade efficiency and number of particle that exit from underflow of the hydroCYCLONE is increased when bigger particles is used.A series of experiments has been carried out in a laboratory with a hydroCYCLONE. Comparison shows that, there is a good agreement between the CFD models and experimental result.

CYCLONEs are conventional equipment for eliminating particulates from gas flows.CYCLONEs’ design is simple and they are reliable. However their efficiency for particulates less than 10 micrometer is very low. For this reason other equipment are used in industry. One of the efficient systems for eliminating particulates from gas, is CYCLONE-scrubbers. CYCLONE-scrubber consists of a CYCLONE and a liquid that is injected by a pneumatic nozzle into gas entrance duct. CYCLONE acts as a space for interaction between liquid and particles and a trap for the liquid-particle. Steady state and a long resident time for a specific particulate, lead to high removal efficiency for sub-micron particles. One of the advantages of CYCLONE-scrubber is low water usage. The ratio of liquid to gas is 0.2-0.5, which is less than other types of scrubbers (0.5-5.0).In this experiment, removal efficiency of CYCLONE for 4.5,9.0 and 13.0 m/s entrance velocity, were 85.5, 85 and 89.9%. In CYCLONE-scrubber, for the same conditions, the removal efficiency were 85.2, 95.6 and 97.4%. Removal efficiency for particles of 0.5 micron in CYCLONE was 3% while in CYCLONE-scrubber it was 63% with l/g=0.2.