2D CFD Modeling of Rapid Water Filling with Air Valves Using OpenFOAM

The rapid filling process in pressurized pipelines has been extensively studied using mathematical models. On the other hand, the application of computational fluid dynamics models has emerged during the last decade, which considers the development of CFD models that simulate the filling of pipes with entrapped air, and without air expulsion. Currently, studies of CFD models representing rapid filling in pipes with entrapped air and with air expulsion are scarce in the literature. In this paper, a two-dimensional model is developed using OpenFOAM software to evaluate the hydraulic performance of the rapid filling process in a hydraulic installation with an air valve, considering different air pocket sizes and pressure impulsion by means of a hydro-pneumatic tank. The two-dimensional CFD model captures the pressure evolution in the air pocket very well with respect to experimental and mathematical model results, and produces improved results with respect to existing mathematical models.

Re-design the use of PV to distribute water from tanks to rural area for Mentawai especially in Central Siberut sub-district

The redesign of the water pump stuck in the district of Central Siberut is reused by using the Solar Panel as an alternative energy source. The materials and tools used are Booster pump, pipe, air valve, wash out, blow off and gate valve. The booster pump is used to pump high pressure water from the tank so that it can reach Saibi village, where Saibi village is the farthest village compared to Simulaklak village, where the distance from the tank to Simulaklak village is only 1.5 km and the tank to Saibi village is 4.5 km the elevation difference between the tank and the village of Saibi is 25 meters above sea level. The total water demand in Simulaklak and Saibi villages is 17.63 liters / second with flow rates in Simulaklak and Saibi villages of 2.25 m / sec and 1.69 m / sec, for the pump head obtained from the tank to Simulaklak village is 72,1 m and the pump head from the tank to Saibi Village is 120.31 m. The standard atmospheric pressure obtained for Simulaklak village is 10,284 mH2O and for Saibi village is 10.301 mH2O. Booster pump is an alternative that can be used for distributing water from the tank to the village.

Analysis of Sub-Atmospheric Pressures during Emptying of an Irregular Pipeline without an Air Valve Using a 2D CFD Model

Studying sub-atmospheric pressure patterns in emptying pipeline systems is crucial because these processes could cause collapses depending on the installation conditions (the underground pipe covering height, type, fill, and pipeline stiffness class). Pipeline studies have focused more on filling than on emptying processes. This study presents an analysis of the following variables: air pocket pressure, water velocity, and water column length during the emptying of an irregular pipeline without an air valve by two-dimensional computational fluid dynamics (2D CFD) model simulation using the software OpenFOAM. The mathematical model predicts the experimental values of the study variables. Water velocity vectors are also analysed within the experimental facility, assessing the sensitivity of the drain valve to different openings and changes in water column length during the hydraulic phenomenon.

Uncertain Gain and Time-Delay Control of 300-kW SOFC-GT

This paper presents a Proportional Integral Derivative (PID) controller design with the presence of an uncertain internal gain and additional time delay in the forward path of a 300 kW Solid Oxide Fuel Cell-Gas Turbine (SOFC-GT). The outputs of the system are turbine speed and the fuel cell mass flow rate. A fixed set of proportional controller coefficients are determined to graphically develop an area of selection for the integral and derivative coefficients of the PID controller. The inputs to the power plant are the electric load and cold air valve. The decentralized controllers are applied to four sub-systems as a Single Input Single Output (SISO). The PID controller coefficients are selected from a singular matrix solution that stabilizes the system and satisfies the internal gain and time delay uncertainties. Two sub-systems are the transfer functions of the turbine speed over the electric load and the cold air valve. The other two sub-systems are the transfer functions of the fuel cell mass flow rate over the electric load and the cold air bypass valve. Multiple options for selecting PID controller coefficients are beneficial to the SOFC-GT plant due to the wide range of operations and internal uncertainty interactions. The specific internal time delay and gain margins increase the reliability and robustness of the SOFC-GT with multiple uncertain parameters.