in the present study, a heterogeneous and homogeneous gas flow dispersion model for simulation and optimization of a large-scale catalytic slurry reactor for the direct synthesis of dimethyl ether (dme) from synthesis gas (syngas) and co2, using a churn-turbulent regime was developed. in the heterogeneous flow model, the gas phase was distributed into two bubble phases including small and large...

Development of autonomous underwater vehicles (AUVs) which meets the design constraints and provides the best hydrodynamic performance is really an important challenge in the field of hydrodynamics. In this paper a new profile is used for designing the hull of AUVs. The nose and tail profiles of an AUV using presented profile is designed such that it can properly consider the length constraints...

The problem of Reynolds-averaged modeling turbulent boundary-layer flow over surfaces arbitrary roughness is studied using the results direct numerical simulations many different rough surfaces. complexity in sublayer such that most effective general strategy appears to be model it as a prescribed velocity profile, either at coarse level conventional roughness-specific log-linear wall function,...

For a long period of time, design and manufacturing technology of high flow rated vertically suspended pumps (VSPs) which have an extensive applications in many industries such as water and wastewater, mining, petrochemical and oil and gas industries, used to be imported from European countries. For the first time in Iran's pump industry, with the support of Ministry of Petrochemical[ah1]  and ...

In an open channel, the transformation from a supercritical flow into a subcritical flow is a rapidly varied flow with large turbulent fluctuations, intense air entrainment, and substantial energy dissipation called a hydraulic jump. New experiments were conducted to quantify its fluctuating characteristics in terms of free-surface and two-phase flow properties for a wide range of Froude number...

Electromagnetic flow metres based on the principles of Faraday's laws of induction have been used successfully in many industries. The conventional electromagnetic flow metre can measure the mean liquid velocity in axisymmetric single phase flows. However, in order to achieve velocity profile measurements in single phase flows with non-uniform velocity profiles, a novel imaging electromagnetic ...

Wind turbines are important devices that extract clean energy from wind flow. The efficiency of wind turbines should be examined under various working conditions in order to estimate off-design performance. Numerous aerodynamic and structural research works have been carried out to compute aeroelastic effects on wind turbines. Most of them suffer from either the simplicity of the modelling ...

Abstract   A new micro combustion concept is described in this work by introducing a new terminology in the micro combustion. The effects of Area to Volume Ratio (AVR) of the micro-combustors were studied to find the best performance of designed micro-combustors. In order to test the feasibility of the designed micro combustors before the actual experiment is conducted, simulation work was perf...

In this work, we first briefly introduce the concept of IP flow classification on a general conceptual level. The intention is to rise above the technological details and create a conceptual point of view on flow classification and closely related issues. Then we move on to study and compare earlier flow classification methods such as the all and selected flow classifier and the packet count fl...

In this paper, 3-dimensional linear instability analysis has been carried out for unsteady pipe flow. An inflectional velocity profile from [2] has been considered and the stability analysis of it has been carried out for (axisymmetric mode) and 0 = n 2 & 1 = n . It was revealed that the profile is unstable for both axisymmetric and non-axisymmetric modes. The mode 1 = n was observed to be most...