In our department, we developed 5KW micro gas turbine and initiated Project Based Learning (PBL) program by utilizing home made micro gas turbine. We started with defining the problem when we introduce such a small size gas turbine to home, convenience store and hotels etc. and try to find the suitable counter measure. Problems to be solved were categorized as interlock system, remote monitoring and control, pressure pulsation in gas supply pipelines and so on. This year, we made two project groups composed of students, professors, gas and turbine company working on developing control system for gas turbine system and the device for suppressing pressure pulsation in supply gas pipeline due to the gas compressor. In this paper, we will introduce how we started PBL program using micro gas turbine, basic principle of our program and the outcome.

A study of transient oil-water flow in hilly-terrain pipelines is described in the present paper. Numerical simulation of terrain slug propagation during the line startup is performed using a novel computer code, mFLOW, for modeling transient flow of two immiscible liquids in pipelines. It is shown that a startup slug may propagate through the system without deformation of its front and tail or may dissipate. The mechanisms of slug dissipation are discussed. It is shown that the fluid pressure response is governed mainly by the process of water holdup wave propagation. It is demonstrated that the analysis of fluid transients in pipelines conveying oil-water mixtures provides useful information for the evaluation of the risk of over-pressurization during the startup period.

A new finite element formulation to analyze stresses and displacements in submarine pipelines during laying operations is presented in this paper. The method is based on the corotational formulation using Bernoulli non-linear beam elements to model the large displacements and rotations of the pipeline. The penalty method is used with spring-contact elements to accurately represent the actual boundary conditions. During the lay barge installation, the pipe rolls over the barge ramp and slides over the stinger before reaching the sea floor. The barge stinger is a ramp over floating supports that holds the pipeline in such a way that the pipe adopts an S-curve during the laying process. Since contact elements allow the pipeline to separate from the stinger at those points where the contact is lost, introducing these elements into the analysis makes it possible to accurately model the actual boundary conditions on the stinger. In addition, the use of contact elements allows the pipe to reach the sea floor at all those points, which naturally require this condition without imposing any displacement boundary condition during the convergence process. A real laying case of an oil transportation submarine pipeline is presented at the end of the paper to validate the results obtained with the developed formulation. A comparison with a finite element formulation introduced by the authors in a previous paper is also presented in order to verify the accuracy and computational effectiveness of the proposed method.

In the course of the U.S. Department of Energy’s (DOE) tank waste retrieval, immobilization, and disposal activities, high-level waste transfer lines have the potential to become plugged. In response to DOE’s needs, Florida International University’s Hemispheric Center for Environmental Technology (FIU-HCET) is studying the mechanism and behavior of pipeline plugging to determine the pipeline operating conditions for safe slurry transport. Transport behavior of multi-species slurry has been studied in a 1-in O.D. pipeline flow loop. The slurry was a five-species mixture of Fe 2 O 3 , Al 2 O 3 , MnO 2 , Ni 2 O 3 , and SiO 2 , which simulated actual waste at the Savannah River DOE site. The relationship between the pressure drop in the straight horizontal sections of the flow loop and the mean slurry flow velocity was determined for two solids volume concentrations of 5.2 and 7.8%. Critical deposition velocity was measured from visual observations. An existing empirical model that predicts the pressure gradient for a single-species slurry flow in a horizontal pipeline was used to describe the pressure drop data.

This work presents a coupled fluid transient model to describe the mixing phenomenon arising in batch transfers in petroleum pipelines. The concentration evolution described by the dispersion of matter at the products’ interface is properly taken into account on the mass and momentum balance equations for the mixture as a whole. The resulting mathematical problem is formed by a system of non-linear partial differential equations which is solved by means of an operator splitting technique, combined with a Glimm’s scheme and predictor-corrector method. The influence of stopping the line during a batch transfer on the mixing volume is preliminarily analyzed for a particular batch.

A numerical model of transient two-phase flow and conjugate heat transfer in a vertical pipeline is presented in the present paper. The drift-flux model is used to describe the fluid flow in the pipeline. The modeling of transient conjugate heat transfer is based on a mathematical formulation in which the pipe wall and the fluid are assumed to be in local thermal equilibrium. The effect of the thermal capacity of the pipe wall is taken into account by an additional term in the energy equation for the fluid flow. Such an approach allows significant simplifying the problem and reducing the computer running time. Numerical simulations of blowdown of a pipeline/riser system were performed. The effect of the pipe wall on the flow behavior was investigated.

A centrifugal compressor performance analysis and assessment procedure is described which is based on the measurement of the basic performance characteristics of the compressor only. It is shown that a useful assessment of the compressor performance can be carried out within the uncertainty bounds of a one-dimensional analysis common to a more detailed experimental study. The analysis procedure provides details of the impeller performance in terms of relative velocity diffusion ratio, and details of the impeller/diffuser interface in terms of the absolute flow angle, incidence angle and Mach number. If the compressor design incorporates a vaneless diffuser the flow angle at the volute inlet can be found, leading to a good assessment of the volute performance. The procedure was applied to a small turbocharger compressor with a vaneless diffuser and a number of gas pipeline compressors with vaned diffusers. The ability to derive the required aerodynamic parameters and the limitations involved are described with reference to one of the gas pipeline compressors and the turbocharger compressor.

A growing number of multiphase technology applications stimulate the development of reliable methods for modeling transient processes in two-phase systems in which the temperature field in the moving fluid and the temperature field in the bounding walls are directly dependent on each other. This situation presents a conjugate heat-transfer problem since the heat-transfer rate at the wall-fluid interface and local fluid conditions are not known a priori, and therefore need to be simultaneously calculated. Examples of such processes include the direct heating of multiphase pipelines, a change of heat load in evaporators of two-phase thermal control systems, startup or shutdown of systems with a two-phase working fluid. In this paper, direct electrical heating of a long two-phase pipeline has been modeled. The modeling of transient two-phase flow and heat transfer in the pipeline is based on two different mathematical formulations. In the first formulation, the transient heat conduction and the forced convection effects are rigorously taken into account. The second formulation assumes that the pipe wall and the fluid are in local thermal equilibrium. The effect of the thermal capacity of the pipe wall is taken into account by an additional term in the energy equation for the fluid flow. Such an approach allows significant simplifying the problem and reducing the computer running time. Numerical simulation of the sudden heat input to the pipe wall has been performed using both formulations of field equations. The practical significance of the results obtained is discussed.

The authors present a methodology for the prediction of performance and emissions of a gas turbine under a wide range of load conditions. The engine, of the aero-derivative type, is employed in a natural gas recompression plant. The paper deals, in its first part, with the reconstruction of the whole operating region of both the gas generator set and the power turbine including its matching with the centrifugal compressor for natural gas delivery in the pipeline. This phase also leads to an effective prediction of pollutant emission, with a chemical kinetics based sub-model. Next, a refined CFD based simulation analyzes a number of operating cases, so providing a detailed insight of the actual phenomena which control the combustion chamber temperature distribution and the activation of the pollutant formation mechanisms.

A numerical method is developed to study the effect of various geometrical and operational parameters on the stability of flow in gas compression systems. It is hoped that this and similar type of studies will help us to understand the effect of coupling of the flow characteristics of a compressor with that of a pipeline. In this study, the gas compression system is assumed to be comprised of a compressor, a throttling valve, and a long pipe. A nonlinear lumped parameter model is used to represent the compressor. The gas flow inside the pipeline is modeled by discrete elements in which the flow is assumed to be one dimensional, viscous, and compressible. The throttling valve is modeled by a single element where the pressure drop across it is predicted through an empirical relation. The governing set of equations for the comprehensive model are linearized using explicit finite difference techniques and then solved for the unknowns of the problem. The results indicate that the amplitude and frequency of the flow oscillations experienced by the coupled system depend on the length of the pipe. The frictional losses seem to dampen the amplitude of the flow oscillations experienced in the compressor and the pipeline.

An extensive investigation surrounding a performance shortfall of a pipeline compressor is presented. Regions of high aerodynamic loss are identified from an extensive flange-to-flange numerical investigation. Special attention is placed on understanding the impact of the interface model between the rotating and stationary components on the performance of each individual component and the whole machine. This process lead to the redesign of the radial inlet, the diffuser region, and the volute. Upon numerical validation of the proposed design changes, the components were manufactured and installed into the compressor that was already operating in the field. “Field” testing showed the new design to have a peak efficiency improvement of 4 points surpassing the contract guarantee.

Crude oil pipelines are always at risk of failing as a result of cracking or corrosion. Failing pipelines can be hazardous to personnel, damaging to the environment, and extremely costly. This makes it essential that all pipelines have a schedule of inspection and maintenance. Robots that inspect pipelines from the outside are preferable to ones that work from the inside, because they can undertake inspections without causing any disruption to production processes and can be put to work at any point of the pipeline. Nevertheless, external robots and associated machinery have several challenges and limitations. This research proposes the design, fabrication, and testing of a novel climbing robot that incorporates a drone-like means of propulsion. The purpose of this robot will be to undertake detection of external defects and to monitor the health of the horizontal and vertical pipelines. This climbing mobile robot is intended to assist the production of new system that will improve pipeline longevity using a minimum of energy and needing little human control. The robot proposed is a modular one, capable of motion on vertical pipes, exhibiting flexibility where there are bends in pipes, can adapt itself to different diameters of pipe, and employs a robust quadcopter propulsion mechanism. The robot itself exists without inspection techniques; it can carry a payload of modules that are incorporated into the design that are able to scan pipelines for inspection. The suggested design has a number of features that will help it to work efficiency, including the ability to carry multiple payloads, the ability to cope with both vertical and curved pipes, the ability to adapt to different sizes of pipe, being able to move autonomously, and being able to transport health monitoring systems. In this paper, a literature survey is presented to show the different types of climbing robots. Compared to the developed robots in literature, the proposed robot is novel in the concept and design. The design of the robot components is discussed in details and the robot prototype is illustrated. This paper focuses on the new mechanical designs for the robot and prototype workability. The robot consists of multiple modules, to include payload modules, suspension modules, and propulsion modules. The suggested innovative design is economical and can be easily installed. Several industries would be very interested in this type of novel reliable means of inspecting pipelines. Future work is presented to show the continuity of the proposed robot development.

Missing data occur when no data value is available for the variable in an observation. In this research, Bayesian data augmentation method is adopted and implemented for prediction with missing data. The data augmentation process is conducted through Bayesian inference with missing data assuming the multivariate normal distribution. Gibbs sampling is used to draw posterior simulations of the joint distribution of unknown parameters and unobserved quantities. The missing elements of the data are sampled conditional on the observed elements. The distribution of model parameters and variables with missing data can be obtained for reliability analysis. Two examples are given to illustrate the engineering application of Bayesian inference with missing data. The first example is to predict the yield strength of aging pipeline by fusing the incomplete surface information with missing data. The predictive performance is compared among direct surface indentation technique, linear regression with complete data and Bayesian inference with missing data. The second example is to predict the fatigue life of corroded steel reinforcing bar from the incomplete input dataset. The predicted fatigue lives are compared with experimental data. Both examples demonstrate that the Bayesian method can deal with missing data problem properly and show good predictive performance.

Systems in service continue to degrade with passage of time. Pipelines are among the most common systems that wear away with usage. For public safety it is of utmost importance to monitor pipelines and detect new defects within the pipelines. Magnetic flux leakage (MFL) testing is a widely used nondestructive evaluation (NDE) technique for defect detections within the pipelines, particularly those composed of ferromagnetic materials. Pipeline inspection gauge (PIG) procedure based on line-scans or 2D-scans can collect accurate MFL readings for defect detection. However, in real world applications involving large pipe-sectors such extensive scanning techniques are extremely time consuming and costly. In this paper, we develop a fast and cheap methodology that does not need MFL readings at all the points used in traditional PIG procedures but conducts defect detection with similar accuracy. We consider an under-sampling based scheme that collects MFL at uniformly chosen random scan-points over large lattices instead of extensive PIG scans over all lattice points. Based on readings for the chosen random scan points, we use Kriging to reconstruct MFL readings over the entire pipe-sectors. Thereafter, we use thresholding-based segmentation on the reconstructed data for detecting defective areas. We demonstrate the applicability of our methodology on synthetic data generated using popular finite element models as well as on MFL data collected via laboratory experiments. In these experiments spanning a wide range of defect types, our proposed novel MFL based NDE methodology is witnessed to have operating characteristics within the acceptable threshold of PIG based traditional methods and thus provide an extremely cost-effective, fast procedure with competing error rates that can be successfully used for scanning massive pipeline sectors.

It is highly desired to develop an inexpensive, wireless embedded sensor system that can provide high-bandwidth measurements of temperature and pressure inside a pipeline for rocket propulsion test applications. The fuel is generally liquid hydrogen and liquid oxygen, which must be kept at cryogenic temperatures. The environment places additional requirements on the design of sensors that is beyond the scope of most available products. Surface acoustic wave (SAW) technology has received considerable attention for harsh environment applications. The ultimate goal of our research is to develop a SAW sensor system for temperature and pressure sensing in the cryogenic environment. In this paper, the temperature testing of the SAW sensor was finished from 30 to 80°C. The strain testing was performed at room temperature. The results have shown that the temperature coefficient of the delay (TCD) at the room temperature is around 74.4 ppm/°C. The Strain coefficient of delay (SCD) of the testing result is 0.38 ppm/με at room temperature.

A new design of an intercept valve assembly of the intermediate-pressure turbine part of greater power output is investigated in terms of pressure losses and flow fluctuations by using measurement on an experimental valve model. In addition, numerical simulations are used to further clarify measured phenomena. For such valve assemblies, it is important to exactly predict pressure losses and avoid danger of vibrations, which are caused by undesirable flow fluctuations, in order to guarantee valve’s efficiency and operational reliability. For this type of valve, it is especially important for turbine operations in partial loads (off-design conditions). Measurements were carried out in the Aerodynamic laboratory of the Institute of Thermomechanics of the Czech Academy of Sciences (IT) in a modular aerodynamic tunnel. Numerical simulations were carried out in the Doosan Skoda Power Company (DSP) by using a package of ANSYS software tools. The experimental valve model is a scaled model of a real valve assembly. It consists of an inlet pipeline, a stop valve and a control valve including its diffuser and outlet pipeline. Measured regimes were defined by a mass flow rate and a control valve cone lift which can be precisely changed. In order to investigate pressure loses, total and static pressures at valve characteristic locations were measured by using Prandtl probes and wall static pressure taps. In order to measure pressure fluctuations, Kulite fast response pressure transducers were used. They were situated near the valve throat where the flow fluctuations, which are strongly related to a flow separation, are the most visible and influential. Measurement results are compared with numerical results and locations with a flow separation were found. In order to reduce this phenomenon, different valve seat angles were also tested. As a result, a valve design could be optimized and, for a pressure loss prediction, a pressure loss model for this new intercept valve assembly could be created. Therefore, pressure losses in similar valve assemblies can be predicted with required accuracy for each new turbine where modern intercept valves are used. This helps to increase steam turbine efficiency and reduce fuel consumption. Based on pressure fluctuations results, operating conditions at which dangerous flow instabilities occur were identified. It was concluded that there is an operating condition border where the flow field starts to be unstable. As a result, the areas of safe and dangerous operating conditions can be predicted so that the operational reliability of the valve can be guaranteed.

It is extremely important and required by thermal power plant to condense the exhaust steam from steam turbine outlets to obtain maximum efficiency on varying loads. Surface type condensers are often used to meet these demands. By condensing the exhaust steam at a pressure below atmospheric pressure, the pressure drop between inlet and outlet of turbine is increased which increases the amount of heat available for conversion to mechanical energy by the turbine. Increasing the heat transfer rate of condenser is an effective method to increase the overall efficiency of a thermal power plant. With condenser playing a vital role in overall plant efficiency, it is important to analyze the areas of fouling/erosion, which reduce the condensation rate. The condenser used in a company has been in operation for many years, so to study the effect of erosion on the condenser pipelines, a computational simulation of a section of the condenser in 210 MW thermal power plant with erosion modeling has been done using Fluent code. To help understand the steam cooling in the condenser, current study analyses a 3D section of the condenser used in a 210 MW thermal power plant using a commercial ANSYS/FLUENT code. A boundary layer coupled mesh is used to simulate the interaction of steam and water with the condenser tubes. Models to simulate the flow of water inside the tubes and low-pressure steam over the tubes are incorporated to show the heat transfer between the steam and water domain through the pipe walls along with incorporation of accretion and erosion model, specially the erosion. Analysis of erosion accretion due to Calcium salts are taken in consideration to interpret the location, where scaling happens and how the yearlong scaling affects the heat transfer ability of the heat transfer tubes. There is one build-in erosion and accretion model in FLUENT, which accounts of erosion/accretion on a surface from solid particle. Although the water is liquid, but the article that is responsible for erosion and accretion is solid, e.g. Calcium salt. The result shows that the heat transfer rate is not constant along the tube over a period due to erosion and untreated hard water used for cooling purpose. The Erosion model predicts the most prominent erosion/accretion sites inside the tubes and stresses on the importance of treatment of the recirculating hard water. A liquid particle erosion can also be modeled in future if needed.

Pre-college project-based learning programs are essential means to increase the students’ interest toward STEM (science, technology, engineering, and mathematics) disciplines and careers. Engineering-based projects have shown significant impact on the students’ interests. Therefore, developing countries are investing strategically in their emphasis to attract students to careers in STEM fields, specifically engineering and medicine. That resulted in a steady expansion of their educational pipeline in STEM; and while that emphasis remains, there is a new and urgent need for expertise in agriculture, environmental science, life sciences and sustainability to support the agriculture industry, which is working to secure independent sources of food for their population. New interventions must be devised to stimulate broader interest in STEM fields while also increasing students’ academic readiness for advanced studies in those areas. To target the requirement of increasing people’s competencies in STEM fields, various programs have been created and designed to inspire and broaden students’ inquisitiveness toward STEM. This paper presents an integrated science-engineering program, called Qatar Invents, designed to support and enhance students’ learning of science concepts while also increasing students’ understanding of global challenges in food and water security. This goes with close connection to the desire to increase in the domestic production of agricultural resources in developing countries in recent years. Qatar Invents would engage students into learning and applying fundamental engineering skills onto relatable real-world issues: namely, in the design of hydroponics systems. Qatar Invents challenges students to develop critical thinking and problem solving skills in solving modern problems through the use of the engineering design process. With hands-on challenges, modeling, and communication training, students are motivated to tackle problems related to food security where they create hydroponics projects. Qatar Invents’ learning objectives included: teamwork, using proper toolbox skills, understanding what is engineering, the process of brainstorming, creating successful innovative designs, building prototypes, and developing presentation skills. Throughout this program, the participants were equipped with hands-on knowledge and critical thinking skills that helped them achieve their objectives. Utilizing the engineering design process, the students worked in small teams to brainstorm ideas and create inventions. The topics covered during the program included the importance of an engineering notebook and documentation, principals of engineering graphics, basics of agricultural science, foundations of hydroponics, the brainstorming practice, generating a decision matrix, proof of concept, and pitching ideas. At the end of the program, the students came up with novel solutions to serious problems wherein unique hydroponics projects were produced and presented to a panel of experts. This program attempts to build bridges between developing countries’ STEM education pipeline and the new demand of talent in the agriculture sector. All pertinent details including the preparation, instructional materials, prototyping materials, and case studies are presented in this paper.

As Pipelines are subjected to bursting failure, the prediction of the burst capacities of corroded pipelines is of significant relevance to the pipeline industry. The Single mode deformation processes, most commonly used in laboratory evaluations like tensile test, may not realistically predict formability performance. Therefore, limit strains tests that use multiple deformation stages would better simulate actual material performance hence bulge test is widely used in pipeline industry for analyzing formability. The tube bulge test is an advanced testing material in which the tube is placed in a die cavity and is sealed from both the ends, the water is injected from the hole inside the sealing punch and hydraulic pressure is increased and the tube gets deformed at the center. The objective of this work is to utilize Taguchi coupled finite element computational methodology to determine the optimum material parameters to attain better formability without necking-splitting failure. To evaluate the dependence of the slope of the forming limit diagram on the material parameters, the simulation under various combinations of strain-hardening exponent (n), plastic strain ratio (r) and thickness of tube (t) is carried out and using thickness gradient criterion, the occurrence of necking i. e. forming limit strains during tube bulging is examined. By observing the optimum condition obtained for maximum plain strain it is concluded that higher the n, r and t more the limit strains will be. It is also observed that among n, r and t, n is the most prominent factor contributing on limit strains followed by r and t. The verification of optimum process parameters obtained through Taguchi technique is carried out using additive model and it is found that the observed value is well in agreement with the predicted value, the extra validation simulation is carried out to validate the Taguchi results.

The objective of this work is to determine the optimum process and geometry parameters to attain maximum bulge height without necking / splitting failure. The effect of process parameters on strain path and its correlation with bulge height is also carried out., ANOVA is used to study the relative contribution of geometry properties, process parameters and tube thickness. It is found that the strain hardening exponent has the highest impact on bulging followed by plastic anisotropy and thickness of tube has a relatively lesser contribution to limit strains of tube bulging. The effects of process parameters, at a specific bulge height, are studied on effective strain distribution and thinning distribution, the homogeneity of which is expressed in the terms of real Kurtosis value. It is concluded that optimum process parameters not only gives less thinning and greater bulge height, it also gives more uniform deformation pattern (thinning and effective strain). The validation of optimum process parameters obtained through Taguchi is carried out using additive model and it is found that the observed value is well in agreement with the predicted value. It is also found that friction has a negative impact on bulge height as well as thinning. This is because higher friction resists the flow of material and causes the material to thin more rapidly at the critical area where necking is taking place. It is also found that bulge height is maximum at higher pressure and higher bulge length and thinning is minimum at lower pressure and higher bulge length.