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Depletion of fossil fuels motivates energy sectors to recover waste heat and utilize the energy using a heat recovery steam generator (HRSG). In the past, the effect of EG flow rate at the gas side of HRSG incorporated with the thermal spreader and supplementary firing was not explored. Therefore, the novelty of the study resides in the effect of exhaust gas (EG) flow rate at gas side HRSG incorporated with thermal spreader and supplementary firing. The impacts of EG flow rate on EG velocity, EG turbulence kinetic energy (TKE), and EG temperature were studied using computational fluid dynamics (CFD). The CFD analysis predicted increased velocity and temperature at the HRSG duct as the EG flow rate increased. The velocity contour showed an increase in velocity from 27.8 to 58.5 m/s. Temperature at the midplane showed an increase from 1092.7 to 1134.0 K when there was an increase in EG flow rate from 36.49 to 76.79 kg/s. The TKE showed a rise in two sections, which were the thermal spreader and duct burner. TKE at thermal spreader and duct burner was 53–227 m2/s2 and 33–154 m2/s2, respectively. Besides, the simulated CFD HRSG duct model was validated using the cogeneration plant data with only a 4% discrepancy, which indicated that the model is reliable for fluid and thermal study. This study's findings aid engineers in understanding EG flow behavior and the impact on HRSG parameters without modifying plant geometry under varied operating conditions. [ABSTRACT FROM AUTHOR]

Fluid–structure interactions may impact the precision and reliability of the unsteady flow and rotor deflection investigation in the centrifugal pump. The energy transfer between fluid and solid could disregard due to ignorance of fluid–structure interaction. This study numerically examines a centrifugal pump's unsteady flow and structural characteristics under varied blade numbers. The entropy generation is computed and simulated numerically, considering the distributions of energy loss in the flow field. ANSYS Fluent and Workbench were employed to simulate the centrifugal pump. The elastic structural dynamic equation is used to predict the structure reaction. The shear stress transport k–ω turbulence model was conducted to simulate the fluid domain. The findings indicated that the head and shaft power increased with the increasing blade numbers at the hydraulic performance. The impeller with seven blades reached the maximum efficiency (78.7%), with an increase of 0.27% relative to the original model. Increasing the number of blades reduces pressure fluctuations at the pump output, and the impeller with nine blades shows a minimum value in pressure amplitude (4960.79 Pa). However, it increases the entropy generation (1.42 W/K) of the centrifugal pump. Variations in blade number affect the distribution and the fluctuation of the equivalent stress and the total deformation. The model with a nine blade exhibited minimum values of equivalent stress and total deformation with 5.74 MPa and 0.046 mm, respectively. This work may improve centrifugal pump operating stability by understanding how blade number affects pump flow and structural behavior and visualizing internal energy loss. [ABSTRACT FROM AUTHOR]

Acupuncture is a form of complementary medicine that has been practiced in China for thousands of years. Adverse effect of acupuncture is rarely reported in local literature. This is a case of a patient who developed bilateral pneumothorax following an acupuncture session. A 63-year-old lady with no significant medical illness presented with sudden onset of shortness of breath half an hour following acupuncture and massage session by traditional medicine practitioner. On examination, she was tachypnoiec and there was reduced air entry bilaterally on lung auscultation. Urgent portable chest X-ray was done and it showed bilateral pneumothorax. Bilateral chest tubes were inserted. Patient was discharged well following five days of hospitalization. As acupuncture is gaining popularity among Malaysian population, medical practitioners need to increase their awareness and knowledge regarding the adverse effect of such alternative practice. [ABSTRACT FROM AUTHOR]

The Morel-Lavallee lesion is a rare soft tissue injury that occurs due to traumatic shearing force on skin surface causing separation of skin and subcutaneous tissue resulting in hematoma. This case report depicts a 22-year-old gentleman who was involved in a motor vehicle accident. He complained of pain and swelling over lower back. He was treated for soft tissue injury and admitted for pain control. One day post-trauma, he complained of increased swelling over the back. His hemoglobin dropped from 12.2g/dL to 10.7g/dL. Diagnosis of Morel-Lavallae lesion was made. Initially no surgical intervention was planned. However, in view of worsening of swelling, bedside aspiration was performed and subsequently a pigtail catheter was inserted to drain the hematoma. In total, 2.05 litre of liquefied hematoma was drained. Thus, Morel-Lavallee lesion is an uncommon soft tissue injury that can cause significant bleeding following trauma. [ABSTRACT FROM AUTHOR]

The rapid development of computing software has facilitated multifarious research in integrated circuit (IC) packaging. Complicated and complex processes can be visualized via simulation modeling with this software. The applications of aided software enhance the fundamental physicochemical understanding and visualization of the IC encapsulation process. In this article, fluid-structure interaction (FSI) during IC encapsulation through computer-aided simulation is reviewed based on the amount of substantial work conducted from the past decades to the present. FSI phenomena in various IC encapsulations, such as wire sweep, paddle shift, lead frame deformation, IC chip, and through-silicon via (TSV) deformation, is considered in the review. The significance and challenges of FSI analysis are also highlighted in this article. [ABSTRACT FROM AUTHOR]

This paper presents three dimensional (3D) simulation of flow visualization in the encapsulation of stacked-chip scales packages (S-CSP), using finite volume method. The S-CSP model is constructed using GAMBIT and simulated using FLUENT CFD software. The epoxy molding compound is Hitachi CEL-9200 XU (LF) and its flow is assumed laminar and incompressible. Cross viscosity model and volume of fluid technique are applied for flow front tracking of the encapsulant. The meshing is performed using tetrahedral elements and the discretization is done by first order upwind scheme. SIMPLE algorithm is selected for solving the governing equations. The top view and 3D view of simulation flow front profiles in the encapsulation process are presented. The percentage of filled volume versus filling time, viscosity versus shear rate and number of voids versus rows of stacked die are plotted. The temperature and pressure distributions within the mold cavity during the encapsulation process are also observed. Further, the possibility and cause of void formation during the encapsulation process are analyzed and discussed in detail. The number of vertical stacking dies and horizontal rows of packages are found to be crucial in the void formation. The numerical results are compared with previous experimental results and found in good conformity. [ABSTRACT FROM AUTHOR]

In this work, the optimal petroleum refinery topology is formulated as a conceptual process synthesis problem using the superstructure optimization approach. We begin with the development of a state-task network (STN)-based superstructure representation that is sufficiently rich to encompass all possible topology alternatives of a conventional oil refinery. Subsequently, a biobjective mixed-integer linear program (MILP) of maximization of profit and minimization of environmental impacts is formulated according to the constructed superstructure. Then, based on a given set of fixed amounts of desired products with available crude oil, the model is solved to generate an optimal topology. The proposed optimization framework also incorporates principles from life cycle analysis (LCA) to account for potential environmental impacts. A numerical example is illustrated to implement the modeling approach. [ABSTRACT FROM AUTHOR]

The proinflammatory transcription factor nuclear factor-κB (NF-κB) has a central role in host defence against pneumococcal disease. Both rare mutations and common polymorphisms in the NFKBIA gene encoding the NF-κB inhibitor, IκB-α, associate with susceptibility to bacterial disease, but the possible role of polymorphisms within the related IκB-ζ gene NFKBIZ in the development of invasive pneumococcal disease (IPD) has not been reported previously. To investigate this further, we examined the frequencies of 22 single-nucleotide polymorphisms spanning NFKBIZ in two case–control studies, comprising UK Caucasian (n=1008) and Kenyan (n=723) individuals. Nine polymorphisms within a single UK linkage disequilibrium (LD) block and all four polymorphisms within the equivalent, shorter Kenyan LD block displayed either a significant association with IPD or a trend towards association. For each polymorphism, heterozygosity was associated with protection from IPD when compared with the combined homozygous states (for example, for rs600718, Mantel–Haenszel 2 × 2 χ2=7.576, P=0.006, odds ratio (OR)=0.67, 95% confidence interval (95% CI) for OR: 0.51–0.88; for rs616597, Mantel–Haenszel 2 × 2 χ2=8.715, P=0.003, OR=0.65, 95% CI: 0.49–0.86). We conclude that multiple NFKBIZ polymorphisms associate with susceptibility to IPD in humans. The study of multiple populations may aid in fine mapping of associations within extensive regions of strong LD (‘transethnic mapping’). [ABSTRACT FROM AUTHOR]

This work proposes a two-stage stochastic programming model with fixed recourse via scenario analysis with incorporation of risk management for an optimal midterm refinery planning that addresses three factors of uncertainties: prices of crude oil and saleable products (in the objective function), product demands (in the RHS coefficients), and product yields (in the LHS coefficients). Compensating slack variables and “discrepancy costs” are employed to explicitly account for constraints' violations to increase model tractability. Variance is adopted as the risk measure, with its shortcomings highlighted and mean-absolute deviation proposed as an improved alternative. A representative numerical example is illustrated. [ABSTRACT FROM AUTHOR]

Four cytokine receptor genes are located on Chr21q22.11, encoding the α and β subunits of the interferon-α receptor (IFNAR1 and IFNAR2), the β subunit of the interleukin 10 receptor (IL10RB) and the second subunit of the interferon-γ receptor (IFNGR2). We previously reported that two variants in IFNAR1 were associated with susceptibility to malaria in Gambians. We now present an extensive fine-scale mapping of the associated region utilizing 45 additional genetic markers obtained from public databases and by sequencing a 44 kb region in and around the IFNAR1 gene in 24 Gambian children (12 cases/12 controls). Within the IFNAR1 gene, a newly studied C → G single-nucleotide polymorphism (IFNAR1 272354c-g) at position −576 relative to the transcription start was found to be more strongly associated with susceptibility to severe malaria. Association was observed in three populations: in Gambian (P=0.002), Kenyan (P=0.022) and Vietnamese (P=0.005) case–control studies. When all three studies were combined, using the Mantel–Haenszel test, the presence of IFNAR1 −576G was associated with a substantially elevated risk of severe malaria (N=2444, OR=1.38, 95% CI: 1.17–1.64; P=1.7 × 10−4). This study builds on previous work to further highlight the importance of the type-I interferon pathway in malaria susceptibility and illustrates the utility of typing SNPs within regions of high linkage disequilibrium in multiple populations to confirm initial positive associations.Genes and Immunity (2007) 8, 570–576; doi:10.1038/sj.gene.6364417; published online 16 August 2007 [ABSTRACT FROM AUTHOR]

Understanding the impact of specific design parameters is essential for enhancing pump functionality and minimizing energy consumption. Alterations in the blade exit angle impact the static pressure, relative velocity, and energy loss within the pump and associated effects on the structural behavior of the impeller. This work investigates the influence of the blade exit angle on the performance, hydraulic, and structural design of the flow passage components of the centrifugal pump. Impeller models with different exit angles (15°, 20°, 30°, 40°, and 55°) were simulated while keeping all other parameters constant. Computational investigations were conducted to examine the flow characteristics of a centrifugal pump with five distinct impellers using the shear stress transport k–ω turbulence model. The numerical investigation was validated with the previous study. The analysis focuses on variations in static pressure, relative velocity, and energy loss. Besides, the energy loss distribution was investigated to determine the total entropy generation (TEG) and entropy generation rate (EGR). The fluid–structure interaction (FSI) for several impeller models was used to examine the effect of the exit angle on the structural properties of the impeller. The results demonstrate that the blade exit angle significantly impacts the pump performance. An increase in blade exit angle has resulted in a rise in head and pressure. Furthermore, the structural behaviors, including the total deformation and equivalent stress, are discussed. The findings of this study provide valuable insights into enhancing energy efficiency and hydraulic design principles of centrifugal pumps. [ABSTRACT FROM AUTHOR]

This article presents a finite volume-based simulation study on the effect of fin length variation on the thermal performance of a bus duct conductor. The study was conducted by developing a numerical model using ANSYS FLUENT. IEC 60439-1 and IEC 60439-2 standards were employed as a guideline to conduct the experimental setup. It was found that increasing the fin length increases the total heat transfer rate. This is due to an increase in the surface area exposed to the fluid and a decrease in the thermal boundary layer thickness. However, it was observed that longer fin lengths contributed to greater frictional forces on the fluid that resulted in a drop in convective heat transfer coefficient. The current numerical study is expected to provide a better understanding of the effect of fin length on the thermal performance of a bus duct conductor. [ABSTRACT FROM AUTHOR]

This study aims to investigate the influence of a conveyor angle on capillary flow during the wave soldering process. Finite volume-based simulation is utilized to study the capillary flow of molten solder. Molten solder filling through capillary action of a pin-through-hole (PTH) is considered at different conveyor angles (i.e., 0–10°). Two PTH positions, namely, center (r/R = 0.2) and offset (r/R = 0.6), are investigated. The effects of a conveyor angle on molten solder filling volume, time, pressure profile, and velocity vector are numerically analyzed. [ABSTRACT FROM AUTHOR]

Cooling periods in the reflow soldering process significantly influence heat transfer coefficient and temperature distribution on solder joints, which constituently contribute to soldering defects. The domain of a desktop lead-free reflow oven was built based on the actual dimensions of a sample in GAMBIT 2.3.16. The model was exported to FLUENT 6.3.26 for further parametric study. After grid independency test, simulation results were validated by experimental data according to the American Society of Mechanical Engineers standard for computational fluid dynamics and heat transfer. Next, a simulation model was used to analyze the correlation between temperatures, heat transfer coefficient, and heat flux against reflow cooling durations. Results revealed that a very high radiation heat flux (122.760 W/m) in a short cooling duration result in unmelted solder powders, which contribute to poor wetting. However, the reduced heat flux of 9.262 W/m affects the mechanical properties of solder balls with its continued cooling. Temperature variation and heat transfer coefficient on different points of the substrate are attributed to the non-uniform airflow distribution during the cooling stage. To sum up, the numerical investigation correlates temperature, heat transfer coefficient, and heat flux distribution on different reflow cooling periods to determine their effect on soldering quality. [ABSTRACT FROM AUTHOR]

This study investigates the effects of printed circuit board (PCB) thickness on adjustable fountain and conventional wave soldering. The pin-through-hole (PTH) vertical fill is examined with three PCBs of different thicknesses (i.e., 1.6, 3.1, and 6.0 mm) soldered through adjustable fountain and conventional wave soldering at conveyor angles of 0° and 6°. The vertical fill of each PCB is the focus. The PTH solder profile is inspected with a non-destructive X-ray computed tomography scanning machine. The percentages of the PTH vertical fill of both soldering processes are also estimated and compared. The aspect ratio of the PCB is also investigated. Experimental results reveal that adjustable fountain wave soldering yields better vertical fill than conventional wave soldering. The vertical fill level of adjustable fountain wave soldering is 100%, 90%, and 50% for the 1.6, 3.1, and 6.0 mm PCB thickness, respectively. FLUENT simulation is conducted for the vertical fill of the solder profile. Simulation and experimental results show that the PTH solder profiles of the two soldering processes are almost identical. The effect of PCB thickness on PTH voiding is also discussed. [ABSTRACT FROM AUTHOR]

This paper presents the implications of the adjustable fountain wave soldering process during pin through hole (PTH) component assembly process. The PTH vertical fill was carried out experimentally by using a newly developed adjustable fountain wave soldering machine ( $${0^{\circ}}$$ conveyor angle). A similar printed circuit board and components were assembled by using a conventional wave soldering machine ( $${6^{\circ}}$$ conveyor angle). This paper focuses on vertical filling by using both wave soldering methods. A non-destructive X-ray computed tomography scanning machine was employed to inspect the vertical fill of each PTH. The percentage of the vertical fill for two different wave soldering machines was analyzed. The PTH filling phenomenon during wave soldering was also discussed. FLUENT software was utilized to simulate the PTH vertical filling of adjustable fountain wave soldering. The volume of fluid model tracked the flow front of the molten solder. The simulation and experimental results showed a nearly identical solder filling profile. The void of the PTH vertical filling was also visualized under an X-ray CT scanning machine. [ABSTRACT FROM AUTHOR]

Improvement of centrifugal pump performance (i.e., head and flow rate) is the main goal for designers since it plays a significant role in most industrial fields. Low flow rate and pump head cause low productivity in the industry. Centrifugal pumps involve several parameters that influence their performance. Thus, modifying some of these parameters within a reasonable range is significant in the centrifugal pump design. The blade numbers are an essential design parameter for pumps, which heavily affects the pump's characteristics. This article reviews the effects of the blade number variation on the centrifugal pumps' performance and synthesizes the current study status. Three research approaches are summarized: analytical studies, numerical simulation, and experimental measurement research to demonstrate blade numbers' influence and characteristics. This article highlighted unsolved issues and implications for future research based on prior research findings. It is clarified that the performance of the centrifugal pump was significantly affected by the number of blades. With increasing blade numbers head, and efficiency would increase until specific values. The blade numbers have optimum values for pumping liquids at the best performance. The data gathered in this review article are expected to contribute a guideline and reference for future research of centrifugal pump performance. It can help the designers estimate the optimum blade numbers to obtain better performance at the best design point of the centrifugal pump. [ABSTRACT FROM AUTHOR]

Purpose: The aim of this study was to evaluate the mechanical stimuli transfer at the bone-implant interface via stress and strain energy density transfer parameters. This study also aimed to investigate the effect of different implant stiffness and parafunctional loading values on the defined mechanical stimuli transfer from the implant to the surrounding bone. Methods: A three-dimensional finite element model of two-piece threaded dental implant with internal hexagonal connection and mandibular bone block was constructed. Response surface method through face-centred central composite design was applied to examine the influence of two independent factors variables using three levels. The analysis model was fitted to a second-order polynomial equation to determine the response values. Results: The results showed that the implant stiffness was more effective than the horizontal load value in increasing the stress and strain energy density transfers. The interaction between both factors was significant in decreasing the likelihood of bone resorption. Decreasing the implant stiffness and horizontal load value led to the increased stress transfer and unexpected decrease in the strain energy density, except at the minimum level of the horizontal load. The increase in the implant stiffness and horizontal load value (up to medium level) have increased the strain energy transfer to the bone. Conclusions: The stress and strain energy density were transferred distinctively at the bone--implant interface. The role of both implant stiffness and parafunctional loading is important and should be highlighted in the preoperative treatment planning and design of dental implant. [ABSTRACT FROM AUTHOR]

: Data on Asian patients who present with reflux symptoms to their primary care physicians are limited.: To determine whether empirical therapy without endoscopy is appropriate for patients who present to their primary care physicians with uninvestigated reflux symptoms without alarm symptoms.: Forty-seven patients presenting with uninvestigated, dominant reflux symptoms but without alarm features to their primary care physicians underwent endoscopy within 2 weeks of referral. Their endoscopic findings were compared with those of 162 primary care patients presenting with uninvestigated dominant dyspepsia. All patients, except those with ulcers, were treated with esomeprazole 20 mg b.d. for 2 weeks. Their treatment response was assessed at 2 weeks using a symptom score.: Among patients with dominant reflux symptoms, 14 (30%) had erosive oesophagitis. No other clinically significant endoscopic findings were detected among them. In contrast, erosive oesophagitis and peptic ulcer were found in 13 (8%,P < 0.001 vs. reflux group), and 12 (7%,P = 0.06 vs. reflux group), respectively, of patients with dominant dyspepsia. Thirty-seven of forty-five (82%) of those with dominant reflux symptoms and 109 of 139 (78%;P = N.S. vs. reflux group) of those with dominant dyspepsia reported≥50% resolution of symptoms after esomeprazole treatment.: Empirical proton pump inhibitor without endoscopy is reasonable for uninvestigated patients who present to primary care physicians with dominant reflux symptoms. [ABSTRACT FROM AUTHOR]

Underfill encapsulation process regularly encounters productivity issue of long filling time that incurs additional manufacturing costs. The package was optimized to attain least filling time while retaining the miniature package size. This paper presents a new analytical generalized filling time chart that was generated using the latest regional segregation-based analytical filling time model. The governing model was well-validated to the industrial underfill benchmark data with discrepancy of less than 10.42%. The filling time chart gives non-dimensionalized filling times at various combinations of bump pitch, gap height, and contact angle. Subsequently, another chart that gives the filling time coefficient was derived from the filling time chart to compute the instantaneous filling time directly. Interestingly, two variation trends of bump pitch were observed from the filling time chart that were distinguishable based on the critical contact angle. When the contact angle exceeds its critical value, there exists the critical bump pitch that restricted the miniature design of the package. On contrary, all past literatures only elucidated one variation trend of bump pitch without introduced the critical contact angle. Overall, the analytical filling time chart benefited the optimization study as it concisely composed all parametric variation trends of filling time as well as the criticality of underfill parameters. Thus, time and effort can be greatly reduced upon compared with the conventional numerical-based optimization work, without compromising the accuracy aspect. [ABSTRACT FROM AUTHOR]

This study investigates the effects of filling level and fillet profile on a solder joint strength between pin-through hole (PTH) and a printed circuit board. The influences of filling level and fillet profile on deformation, von Mises stress and strain are the focus of this research. Five filling levels (20%, 40%, 60%, 80% and 100%) and fillet profiles (0.2, 0.4, 0.6, 0.8 and 1.0) are considered. The Abaqus software is used to examine the PTH structure. A tension test experiment is conducted on a single PTH connector, and its results are compared with the simulation results. The simulation and experimental results show an almost identical linear trend with an average discrepancy of 3.39%. Results show that an increase in the filling level and the fillet profile increases the structural deformation/displacement and the von Mises stress. The displacement and the von Mises stress of the PTH exhibit a linear correlation with the filling level and the fillet profile. This study is expected to provide a good understanding of solder joint strength during wave soldering. [ABSTRACT FROM AUTHOR]

This paper presents the influence of Fe2O3 nanoparticles on the microstructure and fillet height for the ultra-fine electronics assembly in the reflow soldering process. Lead-free SAC solder paste was reinforced with different weighted percentages of Fe2O3 nanoparticles (i.e., 0.01, 0.05, and 0.15 wt.%) using a mechanical solder paste mixer. A new form of nano-reinforced lead-free solder paste was applied to assemble the ultra-fine capacitor (i.e., 01005 size) onto the printed circuit board by applying the reflow soldering method. Focused ion beam (FIB), high-resolution transmission electron microscope (HRTEM) system equipped with energy-dispersive X-ray spectroscopy (EDS), field emission scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy (EDS), and nanoindentation tester, were all used to examine the microstructure, hardness, and the fillet height of the solder joints. The experimental results revealed that nano-reinforced solder with the content of 0.01, 0.05, and 0.05 wt% yielded small changes in the intermetallic layers. Furthermore, applying an increment of Fe2O3 to 0.05 wt% also improved the fillet height. The mechanism of the agglomeration of Fe2O3 in the bulk solder is discussed in this study. Moreover, simulation analysis using the volume of fluid (VOF) and discrete phase method (DPM) was both employed to describe the mechanism of nanoparticle distribution in the solder and the reflow soldering process. The findings are expected to provide profound knowledge and further reference towards the reflow soldering process of the miniaturised electronic package. [ABSTRACT FROM AUTHOR]

The desire of flexibility, light weight and low cost in current electronic device has increased the application of flexible printed circuit board (FPCB). This paper aims to investigate the effect of different Reynolds number ( Re) toward FPCB attached with ball grid array (BGA) package in different arrangements. Actual BGA package with 100 solder joints incorporating FPCB was attached to a fixture in wind tunnel test section to perform FPCB's deflection analysis with different flow velocities and package's configurations. Furthermore, numerical simulation was also performed to obtain numerical deflection and stress value. The findings show that the Reynolds numbers have a substantial effect to the FPCB's deflection and stress. However, the BGA package's positions on the FPCB were found to be insignificant to the responses. The actual BGA package on FPCB as presented in this paper will represent more realistic values of determined FPCB's deflection and stress. [ABSTRACT FROM AUTHOR]

This study investigates the backward compatibility solder joint formed at high peak reflow temperature in aerospace industries. The backward compatibility solder joint is made up of lead-free ball grid array mounted on printed circuit board using tin-lead solders at a maximum reflow temperature ranging from 241.9 to 242.45 °C. The reflow process was conducted under a nitrogen atmosphere in a full convection reflow oven for 80.12-81.27 s. The scanning electron microscopy cross section of the solder ball depicts fairly uniform composition and phase distribution of the Pb-free plastic ball grid array and the tin-lead solder paste across all joints. Nanoindentation tests showed better mechanical properties with higher elastic modulus at 68.64 GPa and acceptable hardness value at 0.26 GPa as compared to those of Sn-Pb and Pb-free solder balls. Intermetallic compound formation at both joints seen in the scanning electron microscopy shows a scallop shape and randomly directed growth because of the uniformly distributed Pb-rich phase on the solder ball. The average intermetallic compound thickness measured by scanning electron microscopy equipped with energy-dispersive X-ray analysis was 3.633 μm, which was less than the specified thickness of 12 μm from the laboratory request. [ABSTRACT FROM AUTHOR]

Molding development and fabrication is costly and always involves part modification. The cost-effective pre-molding analysis is advantageous to engineer and designer prior to the mold design and before mass production. Computer-aided techniques are identified as virtuously cost-effective for pre-molding analysis. The numerical simulation analysis of the injection molding process using ANSYS FLUENT 14 was carried out in the study. The setting pressure and operating temperature were considered for investigation. Influence of these two process parameters to the injection molding process in terms of filing time, flow front advancement, velocity profile were studied. The injection molding and rheological experiments were carried out to substantiate the predictions of ANSYS FLUENT 14 in solving injection molding problems. The results revealed the system pressure is dominant to filling time, flow front advancement and velocity profile. Inversely, operating temperature only vaguely affects the current injection molding process, due to the small variations of polypropylene viscosity at temperature 185-195 $${^{\circ} {\rm C}}$$ . The discrepancies of the simulation and experimental results were only 4.35 and 2.21% for system pressure and temperature, respectively. [ABSTRACT FROM AUTHOR]