Influence of Fuel System Variations on Performance and Emission Characteristics of Combined Air-Wall Guided Mode Modified GDI engine with Alcoholic Fuels and Exhaust Gas Recirculation

GDI engines commercially existed with spray guided mode where the fuel injector placed almost vertically and sprayed fuel is occupied throughout the volume of combustion chamber. With the advanced emission norms, NOx and Soot emissions control is the major task along with lower fuel consumption. To achieve the advanced emission norms, further modifications are required before or during combustion. Combined air-wall guided mode combustion chamber modification is the advanced stage required for further improvement in mixing and superior combustion. Air-wall combined mode involved piston crown shape modification so that the modified shape should impart turbulence effects and divert the fuel/mixture flow towards the spark plug tip to initiate the combustion process. In this study, the combined air-wall guided mode gasoline direct injection engine was tested with gasoline blends using Ethanol, Methanol and N-Butanol at 20, 35 and 50% proportions under specific fixed conditions: 1500 rpm speed, 10% EGR and FIP of 150 bars with three split injections at 320˚, 220˚ and 100˚ before TDC. Tests were conducted over these gasoline blend proportions for engine performance and emission characteristics and achieved beneficial results with E20 gasoline blend over the entire applied torque values.

Experimental and Numerical Studies of Stress Distribution in an Expanding Pin Joint System

Pin joints are widely used mechanisms in different industrial machineries such as aircrafts, cranes, ships, and offshore drilling equipment providing a joint with possibility of relative rotation about one single axis. The rigidity of the joint and its service lifetime depend on the clamping force in the contact region that is provided by the applied torque. However, due to the tolerance needed for insertion of a pin in the equipment support bore, the pin is prone to relative displacement inside the bore. The amplitude of this relative displacement usually increases as time passes and since the material of the support often has lower quality grade than the pin, it leads to creation of slack in the equipment and malfunctioning of the machine. An Expanding Pin System (EPS) can be a solution to this problem where the split sleeve expands to remove the gap while the joint is torqued. Therefore, slack in the joint system disappears and 360° contact area could be achieved, providing a better stress distribution and preventing the stress localization. Determining the EPS preload and the resulting contact pressure and stresses in the joint parts are important to avoid damaging to the contact surfaces of the joints and making the dismantling of the EPS difficult. Therefore, finding the amount of the required torque is a compromise between preventing slack in the EPS and prohibiting damage to the joint parts. Stress analysis in this study is performed based on the industrially recommended torque for the EPS type under study. This article reports the study conducted on the stress distribution and the magnitude of stresses exerted to the equipment support when EPS is installed on the machine. To achieve this purpose and to investigate the stress distribution in the joint, both experimental and finite element (FE) methods were used. The experimental results show how much of the applied energy to the EPS in the form of torque is spent to expand the split sleeve and test boss and also to overcome friction. The finite element analysis provides magnitude and distribution of stresses in the EPS components.

Saint-Venant torsion of orthotropic piezoelectric elliptical bar

The object of this paper is the Saint-Venant torsion of a solid elliptical cylinder made of orthotropic homogeneous piezoelectric material. We find the shape of the homogeneous orthotropic piezoelectric elliptical cross section which does not warp under the applied torque. The sizes of the orthotropic piezoelectric solid elliptical cross section, which has the maximum value of torsional rigidity for a given cross-sectional area, are also determined.

Study of Bondura® Expanding PIN System – Combined Axial and Radial Locking System

Bolted connections are widely used in parallel plates and flanged joints to axially lock using the preload generated by the tightening torque and to constrain radial movements of the flanges by the surface friction between mating surfaces. The surface friction depends on the micro-asperities of mating surfaces; under the influence of vibrations and other external radial loads, these asperities tend to deform over time, resulting in the failure of the connection. The Bondura expanding pin system presented in this article is an innovative axial and radial locking system, in which the failure of bolted connections due to radial movements is eliminated by relying on the mechanical strength of the pin system along with the surface friction. The present study describes an experimental design to verify the maximum possible preload on the axial-radial pin at different levels of applied torque. The article also provides a realistic comparison of the pin system with standard bolts in terms of handling axial and radial loads. With some alterations in the axial-radial pin system’s design, the joint’s capability to resist failure improved appreciably compared with the original design and standard bolts with higher preload. As a result, the estimated capability improvement of the joint against the connection failure due to the external radial load by the axial-radial pin is observed to be more than 200 % compared to standard bolts. Considering the pros and cons of both fasteners, i.e., axial-radial pin and standard bolts, a practical solution can be chosen in which both fasteners are used in a connection, and an optimized situation can be developed based on the working conditions.

Design and Simulation of a Piezoresistive v-Shaped Strain Gauge for Torque Measring

Modeling and simulation of system design adjustment is respectable training for design and engineering decisions in real world jobs. In this paper, the exact perseverance connected with the strain of components is very important for structural designs, analyses, and for excellent control. The information linked to this type of test is usually related to the exact dimensions connected with the pressure within a flexible region. This paper proposed the design and simulation of a torque sensor with a piezoresistive V-shaped strain gauge. The piezoresistive measure of a precious metal for a stable base was made according to the results of an ANSYS simulation. A torque sensor with a piezoresistive V-shaped tension measure on a base was made. The result of the particular simulation shifted the fraction of tension on the base to enable the torque on the substrate to be measured. Theoretical studies on the piezoresistive measure of a metal for the stable base as well as the torque sensor were introduced. A maximum of 127.29 με and a maximum resistance change in gauge equal to 0.091Ω were achieved for an applied torque of 22.0725 Nm. Here, computer systems modeling and simulation are going to be used.

Optimization of Nonlinear Unbalanced Flexible Rotating Shaft Passing Through Critical Speeds

This work studies the nonlinear oscillations of an elastic rotating shaft with acceleration to pass through the critical speeds. A mathematical model incorporating the Von-Karman higher-order deformations in bending is developed to investigate the nonlinear dynamics of rotors. A flexible shaft on flexible bearings with springs and dampers is considered as rotor system for this work. The shaft is modeled as a beam and the Euler–Bernoulli beam theory is applied. The kinetic and strain energies of the rotor system are derived and Lagrange method is then applied to obtain the coupled nonlinear differential equations of motion for 6 degrees of freedom. In order to solve these equations numerically, the finite element method (FEM) is used. Furthermore, for different bearing properties, rotor responses are examined and curves of passing through critical speeds with angular acceleration due to applied torque are plotted. Then the optimal values of bearing stiffness and damping are calculated to achieve the minimum vibration amplitude, which causes to pass easier through critical speeds. It is concluded that the value of damping and stiffness of bearing change the rotor critical speeds and also significantly affect the dynamic behavior of the rotor system. These effects are also presented graphically and discussed.

A protocol for the reduction of applied torque on parent vessel duringelastase-induced aneurysm formation using rabbit animal models

Endovascular therapies for intracranial aneurysms requires animal models for testing the safety andeffectiveness prior to translation to the clinic. Rabbits combined with the elastase and right commoncarotid artery (RCCA) ligation methods is currently a widely used animal model for endovascular de-vice testing. However, the injection of elastase utilizing angiocatheters may potentially exerts adversetorque to the parent vessel and the optimal aneurysm creation period has not been well investigated.In this study, we present a modification to the elastase/RCCA-ligation method by replacing the angio-catheter with a butterfly catheter. Formation of saccular aneurysms was introduced in New Zealandwhite rabbits (n=6), and were maintained for 2, 4 and 6 weeks. The formed aneurysms exhibitedan elongated geometry and were stable during the study period. We found that the modification inthe animal surgery procedure provides improved manipulation of the surgical area, prolonged injec-tion of elastase, and effective degradation of the vascular elastic lamina. Compared to the traditionalelastase/RCCA-ligation method, the present technique can more effectively reduce unwanted injury tothe parent vessel and, therefore, improved stability of the vasculature for testing the efficacy of newlydeveloped endovascular embolization devices.

Effects of the interval geometric deviation and crowning parameters on the automotive differential dynamics

A differential mechanism is an essential component in the majority of automotive applications. Its vitality stems from the fact that it allows a wheel-drive vehicle to take a curve safely. On the other hand, it can ratchet up the vibration in the wheel-drive vehicle due to the excessive gear tooth deflection from applied torque. Some gear tooth modifications can increase or decrease the level of vibration in the mechanism. So far, very little attention has been paid to the effects of the uncertain geometric deviation of the tooth profile and uncertain crowning parameters on the dynamic performance of the mechanism. This study aims to investigate the impacts of these uncertain parameters on the gear systems’ dynamic performance. To this end, the nonlinear interval model of the differential mechanism is proposed. The mesh stiffness for straight bevel gear is modelled through the potential energy method and slice theory, while bearing stiffness elements are calculated at each time step. A refined computational algorithm is proposed to deal with any gear system with multiple interval variables. The scanning method is used as a reference method in this paper. The main outcomes of this study are that the crowning design can slightly reduce the vibration in the mechanism, and the profile errors can increase its vibration level excessively. Besides, the results derived from the refined algorithm show similarities to those determined by the scanning method, and the study shows that the refined algorithm can handle any gear system with uncertain static or time-varying parameters.

Comparative Analysis and Controller Design for BLDC Motor Using PID and Adaptive PID Controller

: This paper describes the Adaptive PID (APID) controller design for speed control preference of Brushless Direct Current (BLDC) motor over the Proportional Integrative Derivative (PID) controller. A methodology of the Adaptive PID controller is proposed, which tunes the parameters automatically. Modeling of the BLDC motor was carried out using PID and Adaptive PID controller, respectively. The behavior of the BLDC motor is analyzed without a controller and by using the conventional PID controller and the new APID controller. Hence the result obtained is analyzed and compared by taking two cases. In the first case of constant speed, the PID controller gave large variability in the initial speed and could not track the desired speed. Also, applied torque could not track the desired speed due to a significant deviation in the actual motor speed. Whereas, in the case of APID, the controller gave small variability in the initial speed and could track the desired motor speed. In the second case of variable speed, the PID controller produced a random response at a variable speed. Whereas, in APID, the controller had an accurate response at variable speed, with no deviation. The result obtained shows that the APID controller provides effective, easier, and fast controlling of the BLDC motor. The output response of the BLDC motor is achieved, and the result is analyzed with the help of utilizing MATLAB and SIMULINK. Background: The BLDC motor is considerably used in the home, transportation, and industrial application. Objective: Comparative analysis of modeling and control of BLDC motor drives for the variable required speed. Method: PID and APID controllers are used in this paper to operate the BLDC motor. Results: A Fixed and variable speed response of both APID and PID controlled BLDC motor is obtained. Conclusion: Response of the speed control of APID controlled BLDC motor is superior to PID controlled BLDC motor at variable speed.

Nonlinear Analysis of Axial Vibration of Five-Axis Machine Tool Worktable With Double Turntable

Studies show that the applied torque and load on the worktable of a dual-turntable five-axis machine tool continuously changes during the machining process. These variations generate vibration in the worktable along the axial direction, thereby reducing the machining accuracy. In order to improve the machining accuracy of the machine tool and the dynamic characteristics of the worktable, this paper first established the nonlinear dynamic equation of the axial vibration of the machine tool table when the worktable is subjected to torque, swing moment and load according to the elasticity of the plate and shell; then according to Galerkin The truncation method solves the dynamic displacement in the axial direction of the worktable, as well as the bifurcation diagram, displacement waveform diagram, phase plane trajectory and Poincaré cross-section diagram of the processing system; Finally, the influence of different parameters, including torque, swing moment, and load on axial vibration of the worktable was analyzed during the tool operation. The obtained results reveal that as the external load changes, the corresponding axial vibration of the worktable is mainly in the state of large periodic motion, where the maximum vibration amplitude reaches 0.09mm, and the external load has the greatest influence on the axial vibration of the worktable. Moreover, the axial vibration of the worktable is affected by the swing moment. More specifically, in the chaotic state of a small period and small area, the maximum vibration amplitude reaches 0.03mm, and the swing moment has a negligible effect on the axial vibration of the worktable. The influence of torque and load on the vibration characteristics of the five-axis machine tool table during machining was studied through experiments. The obtained results demonstrate that non-linear analysis of the table axial vibration of the five-axis machine tool with dual turntables is an effective way to control the stability of the worktable during the processing of the workpiece.