Experimental Study on the Effect of Waste Valve Load and the Volume of Air Chamber on the Performance of the Hydraulic Ram Pump (Hydram) to Water the Paddy Field in Pakandangan, Padang Pariaman Regency

This 2019 DIPA Grand’s research designed and fabricated the size of hydraulic ram (hydram) pump utilized in Pakandangan, Padang Pariaman Regency. There is a water source in this area which has not been functioned adequately to irrigate the paddy field of 10 hectares due to the location of the paddy field which is higher than the water source. However, the use of designed hydram pump has no been maximized as the pump’s optimal performance was not determined yet. Therefore, a hydram pump was designed by varying the load of waste valve in the weight of 400 g, 600 g, 800 g, 1,000 g, and 1,200 gr. It was also varied in the volume of the chamber when the pump operated which were 4.86 lt, 5.76 lt, 6.48 lt, 7.29 lt, and 8.1lt. The height (Hd) of the inlet pipe was 1 m, and the lift height (Hs) of the outlet pipe was 5 m. The results obtained from Pump performance increases with increasing cylinder volume. The increase in the load of the exhaust valve volume of the tube remains a significant decrease. Hydram pump performance occurs at a load of 400 g with a tube volume of 8.1 l with an efficiency of 53%

Analysis for effect of pores on acoustic performance of reactive muffler

The major source of noise pollution was an internal combustion engine. Henceforth, the design of the engine exhaust system was a tough challenge for automotive industries. The mufflers have been used to moderate the exhaust noise from the engine to the neighboring atmosphere. So in domestic as well as the industrial application, it is required to reduce noise levels to prevent human hazards. The performance of muffler is measured in terms of transmission loss. The transmission loss of reactive muffler is depending on its geometry. This article describes the effects of pores at the inlet pipe and outlet pipe of the reactive muffler on its performance capacity at a target frequency. It is found that the muffler performance is dependent on the number and position of pores. The single chamber and double chamber reactive mufflers are used for the study. The numerical analysis is performed by COMSOL Multiphysics software. The numerical analysis result of the different models of the muffler is compared with experimental analysis. The purpose of the study is to investigate the effect of pores in inlet and outlet pipe to maximize the TL at the target frequency of reactive muffler.

Simulasi Sistem Aliran Massa Pneumatic Grain Conveyor Kapasitas 135 Ton/Jam

Abstrak Pneumatic grain conveyor adalah sebuah alat untuk memindahkan benda yang berbentuk serbuk atau butir dengan memanfaatkan udara sebagai media pemindahan. Conveyor yang cocok digunakan untuk memindahkan butiran-butiran seperti gandum dengan cepat adalah bertipe pneumatic grain conveyor yang memanfaatkan fluida udara sebagai media untuk memindahkan butiran. Proses simulasi ini dilakukan untuk membuktikan sejauh mana kapasitas perancangan 135 ton/jam dapat dicapai oleh conveyor hasil perancangan. Pneumatic grain conveyor yang dirancang menggunakan sistem tekanan kombinasi, proses simulasi dilakukan pada jalur aliran gandum yang meliputi 3 bagian menyambung yaitu inlet pipe, cyclone, dan outlet pipe. Boundary conditions pada bagian inlet pipe menggunakan data dari hasil perancangan, sedangkan pada cyclone dan outlet pipe menggunakan data dari hasil simulasi pada bagian sebelumnya. Hasil simulasi menunjukkan bahwa kapasitas pemindahan dari conveyor adalah sebesar 26,653 ton/jam. Laju aliran gandum dapat mencapai fasa dilute phase serta cyclone berfungsi dengan baik dalam memisahkan gandum dengan udara. Kata kunci : pneumatic grain conveyor, inlet pipe, cyclone , outlet pipe, simulasi. Abstract Pneumatic grain conveyor is a tool for moving objects in the form of powder or grain by utilizing air as a transfer medium. Conveyors that are suitable for moving granules quickly such as wheat are pneumatic grain conveyor, that use air fluid to move the grain. This simulation process is carried out to prove the extent to which the design capacity of 135 tons / hour can be achieved by the designed conveyor. Pneumatic grain conveyor designed using a combination pressure system, the simulation process is carried out on the grain flow path which includes 3 connecting parts, namely inlet pipe, cyclone, dan outlet pipe. Boundary conditions in the inlet pipe section use data from the design result, while the cyclone and outlet pipe section use data from the simulation results in the previous section. The simulation results show that the displacement capacity of the conveyor is 26.653 tons / hour. The flow rate of wheat can reach the phase of the dilute phase and the cyclone works well in separating wheat with air. Keywords : pneumatic grain conveyor, inlet pipe, cyclone, outlet pipe, simulation.

Influence of the distance from an obstacle to the outlet pipe of the radiator fan case of the automotive engine cooling system on the distribution of air flow

The article presents the methodology and results of the study of the influence of the distance from the obstacle to the cut of the outlet pipe of the fan case of the cooling system of the automobile engine on the nature of the air flow distribution in front of the radiator. The studies were carried out on a specially made laboratory installation that provides measurement of the air flow velocity at fixed points in front of the radiator. As a result of the research, there were obtained response surfaces that describe the distribution of the air flow in front of the radiator at different distances from the obstacle to the outlet of the fan case. On this basis, there was determined the optimal distance from the obstacle, which provides the most uniform radiator blowing.

PROCESSING OF WASTE COAL FINES WITHOUT ACCESS TO OXYGEN

The subject of research in this work is the processing of waste coal fines using a pyrolysis plant. The aim of the study is to obtain semi-coke and pyrolysis gas in the process of processing waste coal fines without oxygen. The process of thermochemical processing of coal fines is carried out by the principle of embedding a pyrolysis unit in a pyrolysis unit, or a second pyrolysis unit of a reduced size is installed inside the improved design of the pyrolysis unit using a specially withdrawn hole. To obtain the result of the study, the main pyrolysis unit, first, we will load the main pyrolysis unit with coal and then install the built-in (new) pyrolysis unit by preloading it with coal fines, and then we will make connections with the outlet pipe and fully load the main pyrolysis unit. We attach a distributor tee, a waste material container and a receiver for collecting pyrolysis gas to the outlet pipe. Experimental research is carried out on the coals of the Abshyr-ata and Kozho-kelen deposits, and for the reliability of the obtained research result, we will measure the main parameters of the studied coals until the final product is obtained. To obtain the result of the study, the main pyrolysis unit, first, we will load the main pyrolysis unit with coal and then install the built-in (new) pyrolysis unit by reloading it with coal fines, and then we will make connections with the outlet pipe and fully load the main pyrolysis unit. We attach a distributor tee, a waste material container and a receiver for collecting technical gas to the outlet pipe. Experimental research is carried out with coals of the Abshyr-ata and Kozho-kelen brands, and for the reliability of the obtained research result, we will measure the main parameters of the studied coal grades until the final product is obtained. With the help of this unit, the process of upgrading waste of coal fines and low-grade coals of Kyrgyzstan is carried out. The developed installation can be used in the heat and power industry of the Republic and research institutions.

Numerical Study of the Unsteady Flow Inside a Centrifugal Fan and its Downstream Pipe Using Detached Eddy Simulation

The 3-D unsteady turbulent flow inside a centrifugal fan and its downstream pipe is investigated at the best efficiency point (BEP) flow rate using the computational fluid dynamics (CFD) package ANSYS FLUENT. The impeller with an outlet diameter of 400 mm has 12 forward curved blades. The computational domain comprises four parts: the inlet part, the impeller, the volute, and the downstream pipe. The flow domain was meshed in ANSYS ICEM-CFD with structured hexahedron cells, and nearly 9 million cells were used. The Detached Eddy Simulation (DES) turbulence modelling approach was employed with this fine enough mesh scheme. The impeller was set as the rotating domain at a speed of 2900 rpm. A sliding mesh technique was applied to the interfaces in order to allow unsteady interactions between the rotating impeller and the stationary parts; the unsteady interactions generate pressure fluctuations inside the centrifugal fan. One impeller revolution is divided into 2048 time steps, in order to capture the transient flow phenomena with high resolution. Monitoring points were set along the volute casing profile, and along the downstream pipe centerline. When the numerical simulation became stable after several impeller revolutions, the statistics of the unsteady flow was initiated with a total of 16384 time steps (8 impeller revolutions) data. The time history data of the pressure and velocity magnitude at the monitoring points were saved and with Fourier transform applied to obtain the frequency spectra. The time-averaged flow fields show clearly the static pressure rises gradually through the impeller, and further recovers from the velocity in the volute, and decreases gradually along the downstream pipe due to the friction. The mean pressure at the pressure side of the impeller blade is larger than it at the suction side, forming the circumferential nonuniform flow pattern. Owing to the forward-curved blades, large velocity region exists around the impellor exit, and the maximum velocity near the trailing edge can reach 1.5u2, where u2 is the circumferential velocity at the impeller outlet. The root mean square (rms) value distribution of pressure fluctuations show that most parts inside the centrifugal fan undergo large pressure fluctuation with the magnitude about 10% of the reference dynamic pressure pref = 0.5ρu22; the maximum value locating at the tongue tip can reach 30% of pref. The pressure fluctuation magnitude decreases quickly along the outlet pipe: after 5D (D is the outlet pipe diameter) the magnitude is 0.5% of pref. The pressure and velocity fluctuation spectra at the monitoring points in the volute show striking discrete components at the blade-passing frequency (BPF) and its 2nd, 3rd harmonics. The BPF component has the maximum value of 15% of pref in the tongue region, and it decreases dramatically along the downstream pipe with the amplitude less than 0.2% of pref after 5D distance.

Numerical Investigation on the Transient Flow of a Boiler Circulating Pump Based on the Shear Stress Transport Turbulence Model

Based on the shear stress transport (SST) turbulence model, the influence of different outlet pipe angles on the head and efficiency of a boiler circulating pump was analyzed. When the outlet pipe angle changed from 115° to 130°, the head and efficiency of the pump reduced significantly. The boiler circulating pump with 115° outlet pipe angle was selected as the further research object, and the reliability of the numerical simulation was verified by experiments. The transient flow of the prototype pump under the design flow rate condition (1.0Qd) and four other flow rate conditions (0.6Qd, 0.8Qd, 1.2Qd, and 1.4Qd) was studied. The results show that, under the conditions of design flow and large flow rate (1.0Qd, 1.2Qd, and 1.4Qd), the centrality and regularity of radial force distribution are obviously better than those of small flow rate (0.6Qd, 0.8Qd). The leakage of the rear seal ring is less than that of the front seal ring under five flow rate conditions. As the flow rate increases, the leakage of front and rear seal rings decreases, and the leakage ratio of front and rear seal rings increases. The energy loss of the rear cover plate is greater than the energy loss of the front cover plate under five flow rate conditions. With the increase in flow rate, the total loss energy of the prototype pump decreases first and then increases, and the energy loss of the disc becomes larger and larger.

Numerical approach for prediction of turbulent flow resistance coefficient of 90° pipe bends

In the present study turbulent flow in a circular cross-sectioned 90° smooth-walled pipe bend has been investigated numerically. The geometry of the model consisted of three sections: a straight inlet pipe of length 52 diameters, a 90° bend with radius of curvature 1 diameter, and a straight downstream pipe of length 52 diameters. Reynolds numbers from 5,000 to 120,000 were considered. The numerical model was developed using COMSOL Multiphysics and all turbulent flow simulations were performed using the standard k- ε turbulence model. The main objective of this work was to estimate the resistance coefficient of pipe bends using not only pressure drop but also information of the flow behavior far downstream in the outlet pipe. Wall static pressure and velocity fields of the secondary flow were illustrated to provide information of the flow behavior in the bend and downstream of the pipe bend. Furthermore, swirl intensity of secondary flow was presented in order to describe its behavior as the flow develops in the outlet pipe. Estimations of resistance coefficient were calculated and compared to other studies. It was found that the procedure used in this study is a viable method for a more accurate estimation of resistance coefficient values for turbulent pipe flows containing 90° bends. For best accuracy in either experimental or computational analyses, it is recommended that pressure in the downstream tangent be measured at no less than fifty diameters downstream of the bend to avoid influence of the secondary flow.