abstract due to transmission losses and lack of initial flow, flood routing in ephemeral streams is not possible with common methods and it is necessary the flood routing models have been developed for these streams. therefore in this study a computer model for natural river cross section has been developed in that after linearization of partial differential equations of unsteady none uniform f...

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In this paper, numerical investigation of upward two phase flow of air-water has been studied. Different conditions of flow regimes including annular, wispy annular, slug, churn and bubbly are simulated based on Hewitt and Roberts map, and a good agreement between the experimental data of the map and the numerical simulation has been observed. Accordingly, a proper CFD model in CFD software of ...

The value of the permeability in fluid flow through porous media is important for process investigation. In low Reynolds number, the classic Darcy’s law is suitable for simulation of fluid flow. In this paper, an experimental study for evaluation of preformed fiber permeability has been done. Also, the deviations from the classical Darcy law by experimental and numerical simulation of the N...

An analytical investigation is conducted to study the unsteady free convection heat and mass transfer flow through a non-homogeneous porous medium with variable permeability bounded by an infinite porous vertical plate in slip flow regime while taking into account the thermal radiation, chemical reaction, the Soret number, and temperature gradient dependent heat source. The flow is considered u...

different approaches have been presented for estimating river environmental flow which hydrological approach has a lot addressed because of its need to access to limited data and moderately rapid assessment. this approach incorporates various methods therefore comparison between results of different methods is essential. the objective of this study is to investigate and compare the consequences...

A newly developed heavy duty diesel engine in dual fuel mode of operation has been studied in detail. The main fuel would be natural gas and diesel oil as pilot injection. The importance and effects of mixture preparation and formation through ports, valves and in cylinder flow field with different swirl ratio and tumble on diesel combustion phenomena is an accepted feature which has been studi...

With the wind permanent flow in the cities, obtaining the minimal pollution in the environment is accessible. Different policies have been considered for optimization of cities such as attachment and or reduction of building parts like air-traps, ceiling forms and so on. Due to population growth in cities and the increasing need for resettlement these people in the cities, inevitably, to the hi...