Dill is one of the most important plants in the world because of its medicinal properties and it is widely used as a vegetable in the most parts of Iran. In the present study a new solar dryer with FINNY, PERFORATED absorber plate COLLECTOR was utilized to dry fresh dill. The dryer was comprised of a solar COLLECTOR, a product container, a fan and a drying air temperature controller. The temperature controller was used as a control system to regulate the drying air temperature. Thermal performance of the dryer with FINNY, PERFORATED solar COLLECTOR was compared with that of a simple flat plate solar COLLECTOR at different airflow rates. The effect of drying air temperature at three levels (45, 55 and 65oC), the product size at three lengths (3, 5 and 7 cm) and two different modes of drying (mixed and indirect) on the dryer performance was investigated. The results showed that the FINNY, PERFORATED absorber plate solar COLLECTOR could improve the thermal efficiency about 11% in comparison with the flat plate COLLECTOR and the highest thermal efficiency was achieved at the maximum airflow rate. Meanwhile, increasing the air temperature and decreasing the product size caused a significant reduction in energy consumption. Solar fraction reduced by increasing the air temperature. Finally a maximum dryer efficiency of 70% was observed at air temperature of 65oC, product size of 3 cm with mixed mode drying.

Experiments were carried out for the numerical investigation of heat transfer enhancement in a solar air COLLECTOR using different types of baffles and vortex generators. In this study, the vortex generator was implemented to increase the efficiency of the solar air COLLECTOR. The variations in Nusselt number, pressure drop, friction coefficient, and thermal and exergy efficiency in four COLLECTORs with different baffles arrangement (type A, B, C, D) were investigated. Type A was chosen as the optimum COLLECTOR for implementing the vortex generator on the absorber surface. In the solar air COLLECTOR the effects of using a novel vortex generator-the PERFORATED Delta Wing Vortex Generator (PDWVG), in comparison with a flat one-the Flat Delta Wing Vortex Generator (FDWVG), were considered. In order to determine the maximum efficiency of the solar air COLLECTOR, four different pitch ratios of vortex generators were studied. The Nusselt number and pressure drop increased with the Reynolds number but the friction coefficient decreased with Reynolds, the experimental and numerical results revealed that the thermal and exergy efficiency decreased from a specific range. The comparison of PDWVG and FDWVG showed that the presence of holes on the novel vortex generator led to reduced pressure drop and increased heat transfer between the airflow and the absorber surface. Increasing the number of vortex generator rows had a slight effect on increasing the studied parameters. The results showed that COLLECTOR type A with ep=0. 55 of PDWVG improves the energy and exergy efficiency 4. 43% and 5. 29% respectively.

The indispensable vital structure in any harbor is a breakwater in order to make available calm water region inshore. Pile breakwater can be employed as small coastal-protection structure where tranquility required is low. This study is concerned with CFD study on performance of PERFORATED hollow pile to dissipate wave energy and the novelty of this investigation is the role of perforation layout to dissipate energy of water. Pile models under two different incident waves with constant water depth and wave amplitude have been classified into two groups with two different wavelengths, making a total of 10 models which has been simulated numerically by computational flow solver FLOW 3D. The analytical results of simulations show changes in the velocity profiles after piles while dissipation happened in the vicinity of the pile. The results implied that the PERFORATED models can perform better than the nonPERFORATED ones and energy dissipation was found much more significant in PERFORATED piles because dissipation goes on for about 2. 5 m after the pile for the PERFORATED case, while for the non-PERFORATED case this distance reduce to 1. 5 m after pile.

In this paper, an experimental solution has been developed for evaluation of transmission coefficients of water waves through single PERFORATED sheets and upright PERFORATED wave filters. Two series of laboratory tests were carried out on single PERFORATED sheets and upright PERFORATED wave filters. Two kinds of PERFORATED sheets and a wide range of wave steepness were used in these tests. The effects of wave and PERFORATED plate parameters were investigated on the coefficient of wave transmission. Moreover, it is shown that the transmission coefficient through single PERFORATED sheets and upright PERFORATED wave filters can be calculated using the wave-screen parameter defined by Chegini (1995). Finally, a new equation is presented to calculate the wave transmission coefficients through these porous structures.

This paper deals with the performance of a heat pipe solar COLLECTOR. The solar COLLECTOR consisted of an interconnected heat pipe so as to reduce the production cost by using an interconnected heat pipe because all the heat pipes can be evacuated, sealed and tested at once. Performance of a prototype of the heat pipe solar COLLECTOR was experimentally examined, and the results were compared with those obtained through theoretical analysis. The results shown in this paper seem feasible.