Computer modeling and simulation of a single cylinder, 4-stroke cycle, gasoline fueled spark ignition engine

The simulation model developed is a quasi-static frictionless piston, semi-perfect gas working fluid with transient heat, mass, and work transfer ICE model. It runs on the Interactive Simulation (ISIM) software. Simulation test runs were made to evaluate effects of engine speed, air-to-fuel ratio, extent of combustion, and intake and exhaust valve timing. The model is limited by the exclusion of momentum effects from the set of constraints considered. Moreover, actual fuel flow control, i.e. during governing, is not integrated in the model. This may be seen from the results of engine test runs on the 3 hp, 63.2 mm bore x 46.8 mm stroke, single cylinder, horizontal, air-cooled Tecumseh engine whose parameters are used in the simulation runs

Development of a ternary blend geopolymer from coal fly ash, coal bottom ash and rice husk for low heat transmission and fire resistant material

Geopolymers have been considered a promising replacement for ordinary Portland cement (OPC) as a binding material. As geopolymers can be produced from alumina- and silica- rich industrial and agro-industrial waste materials and by-products such as blast furnace slags, mine tailings, coal ashes, etc., geopolymer technology has a great potential for environmental management of these types of wastes towards closing the loop in a circular economy. Further, the geopolymerization process has characteristic lower emissions and lower energy consumption vis- à-vis OPC which translates to positive environmental initiatives. In this study, the ternary mixture of the alumina- silica- rich materials coal fly ash, coal bottom ash and rice husk ash was evaluated for developing low heat transmission and fire resistant materials. Conventional geopolymer formulations use mainly coal fly ash with the coal bottom ash usually relegated to the ash ponds/ landfills. But in this study, coal bottom ash has been shown as a significant combining element in the geopolymer mixture. The rice husk ash being light and having very low thermal conductivity was able to pull lower both the heat transmissibility and volumetric weight of the resulting geopolymer. Via optimization using response surface methodology (RSM) with desirability functions, an optimum ternary mixture of 85% coal fly ash - 10% coal bottom ash - 5% rice husk ash met the performance requirements of OPC concrete according to ASTM standards for lightweight, low heat transmission, medium load masonry applications. Fire resistance tests based on ASTM E119 show better performance than similar samples of OPC specimens. Also, environmental impact analysis via embodied energy and CO2 estimation obtained 63% reduction in embodied energy and 84% reduction in embodied CO2 vis-à-vis OPC. The study has thus presented two main elements: (1) the development of a lightweight, low heat transmission, and fire-resistant material and (2) a waste management option for coal ashes and rice husk waste

Calorie burn profile among twenty-four Filipinos who stride along Mt. Pingas

The calorie burn profile of twenty-four Filpinos who stride along Mt. Pingas at Pakil, Laguna was covered. We intend to determine the calorie burn profile among twenty-four typical Filipino citizens of Pakil, Laguna as a function of weight, age, blood pressure, and pulse rate. The analysis of the data can serve as a pilot test in initiating a nationwide baseline data on the calorie burn per stride among Filipino walkers. We selected twenty-four Filipinos from Pakil, Laguna who does not have any history of hypertension, heart-related problems, pulmonary-related problems, drug dependency, alcoholic dependency, and other debilitating illness during the health awareness week in Pakil, Laguna. Vital statistics of each participant were taken before making the stride along Mt. Pingas. Number of strides was also recorded with the use of portable pedometer. No significant trend can be established between the calories burned with varying weights, However, results have shown a linear trend between calorie burn during ascension and calorie burn during the descent thru linear regression analysis

An experimental study on axial flow pump operated as a turbine model with draft tube

An experimental investigation concerning the analysis of system performance for axial flow pump operated as a turbine with draft tube is presented. The dimensional analysis is used to derive the functional relationship between discharge coefficient and energy coefficient. The two parameters and the one-dimensional flow theory are found useful to establish the turbine performance diagram. In this study, the Reynolds number in the upstream part of an axial flow turbine model is ranging from 90,000 to 170,000. © 31st IAHR Congress 2005: Water Engineering for the Future, Choices and Challenges. All Rights Reserved

Mechanical and thermal properties of geopolymers from mixtures of coal ash and rice hull ash using water glass solution as activator

Geopolymers, from industrial wastes such as blast furnace slag, red mud, and coal ash, among others, have emerged as technically viable, economically competitive, and environmentally attractive supplements and even alternatives to ordinary Portland cement (OPC). Furthermore, while the most impact shall be achieved with large-scale use in the general building and structural sector, as replacement or supplement to OPC, the properties of these geopolymers may be optimized for special niche applications. One of these applications is for light weight, low thermal conductivity, heat resistant, and moderate strength cement binder for low rise residential buildings. In this study, compressive strength, heat resistance, volumetric weight, mass loss, water absorption and thermal conductivity of geopolymers formed from mixtures of coal bottom ash and rice hull ash (CBA-RHA) and coal fly ash and rice hull ash (CFA-RHA) with sodium silicate solution (modulus 2.5) as activator were evaluated. Using mixture design and the JMP statistical software, the CBA-RHA combination at a mass ratio of 46% CBA, 32% RHA with 22% WGS gave properties at maximum desirability of 17.6 MPa compressive strength, 1640 kg/m3 volumetric weight, 273 kg/m3 water absorption, 28 MPa compressive strength after high temperature exposure (1000oC for 2 hours) with 4.4% mass loss, and 0.578 W/m-K thermal conductivity. On a performance basis, even as the geopolymers are formed as paste, these properties fall within the standards for lightweight OPC based-concrete with strength requirements for residential buildings. The low thermal conductivity and higher strength after high temperature exposure vis-à-vis OPC are additional advantages for consideration. © 2015, Gadjah Mada University. All rights reserved

Reinforced alkali-activated concrete with induced corrosion

Reinforced concrete comprising of deformed steel bars is the common structural material in construction. The problem of this composite material is the corrosion of deformed steel bars inside the concrete that weakens the structure over time. In this paper, investigation on the two types of reinforced concrete were used: alkali-activated concrete (AAC) and ordinary Portland cement (OPC) concrete beams. In addition, Impressed Current Technique (ICT) was made to accelerate corrosion before performing flexural bending test. The use of a non-destructive test which is the digital image correlation (DIC) technique during the flexural loading test on the two types of beam were considered to monitor the strain values against load. It was concluded that AAC mixture 1:1:2 (coal fly ash: fine aggregate: coarse aggregate) with 12M Molarity and water binder ratio of 0.52 produced the lowest corrosion rate over time for all the beams. In addition, the strain values of the AAC mixture produced ductile behavior with strain softening effect on the third point bending load test where the location of the force was applied. © 2019 International Committee of the SCMT conferences. All rights reserved