Abstract: the intension in this work is to investigate the effect of
different bending manifold pipes on engine performance for different
engine speed. Power, Torque, and BSFC were calculated and
presented to show the effect of varying bending pipes angles on them
for all cases considered. A special program used to carry out the
calculations. A simulation model for 4-cylinders spark ignition
engine with turbocharger has been built and calculated. The analysis
of the results shows that for 120o angle the torque increases about
40% at 3000 rpm and 25% at 4000 rpm without changing in fuel
consumption. For 90o angle the increment in torque is about 10 %.
For the same bending angle the increment in brake power is around
40% at 3000 rpm and 25% at 4000 rpm. The increment in fuel
consumption is about 12% for 60o and 30% for 90o between (6000-
7000) rpm.
Abstract: Numerous experimental tests for post-installed anchor systems drilled in hardened concrete were conducted in order to estimate pull-out and shear strength accounting for uncertainties such as torque ratios, embedment depths and different diameters in demands. In this study, the strength of the systems was significantly changed by the effect of those three uncertainties during pull-out experimental tests, whereas the shear strength of the systems was not affected by torque ratios. It was also shown that concrete cone failure or damage mechanism was generally investigated during and after pull-out tests and in shear strength tests, mostly the anchor systems were failed prior to failure of primary structural system. Furthermore, 3D finite element model for the anchor systems was created by ABAQUS for the numerical analysis. The verification of finite element model was identical till the failure points to the load-displacement relationship specified by the experimental tests.
Abstract: In this paper a sliding-mode torque and flux control is
designed for encoderless synchronous reluctance motor drive. The
sliding-mode plus PI controllers are designed in the stator-flux field
oriented reference frame which is able to track the mentioned
reference signals with a minimum pulsations in the state condition. In
addition, with these controllers a fast dynamic response is also
achieved for the drive system. The proposed control scheme is robust
subject to parameters variation except to stator resistance. To solve
this problem a simple estimator is used for on-line detecting of this
parameter. Moreover, the rotor position and speed are estimated by
on-line obtaining of the stator-flux-space vector. The effectiveness
and capability of the proposed control approach is verified by both
the simulation and experimental results.
Abstract: It is believed that continuously variable transmission (CVT) will dominate the automotive transmissions in the future. The most popular design is Van Doorne-s CVT with single metal pushing V-belt. However, it is only applicable to low power passenger cars because its major limitation is low torque capacity. Therefore, this research studies a novel dual-belt CVT system to overcome the limitation of traditional single-belt CVT, such that it can be applicable to the heavy-duty vehicles. This paper presents the mathematical model of the design and its experimental verification. Experimental and simulated results show that the model developed is valid and the proposed dual-belt CVT can really overcome the traditional limitation of single-belt Van Doorne-s CVT.
Abstract: Doubly fed induction machines DFIM are used
mainly for wind energy conversion in MW power plants. This paper
presents a new strategy of field oriented control ,it is based on the
principle of a double flux orientation of stator and rotor at the same
time. Therefore, the orthogonality created between the two oriented
fluxes, which must be strictly observed, leads to generate a linear and
decoupled control with an optimal torque. The obtained simulation
results show the feasibility and the effectiveness of the suggested
method.
Abstract: This paper presents a mean for reducing the torque
variation during the revolution of a vertical-axis wind turbine
(VAWT) by increasing the blade number. For this purpose, twodimensional
CDF analysis have been performed on a straight-bladed
Darreius-type rotor. After describing the computational model, a
complete campaign of simulations based on full RANS unsteady
calculations is proposed for a three, four and five-bladed rotor
architecture characterized by a NACA 0025 airfoil. For each
proposed rotor configuration, flow field characteristics are
investigated at several values of tip speed ratio, allowing a
quantification of the influence of blade number on flow geometric
features and dynamic quantities, such as rotor torque and power.
Finally, torque and power curves are compared for the analyzed
architectures, achieving a quantification of the effect of blade number
on overall rotor performance.
Abstract: Horizontal platform system (HPS) is popularly applied
in offshore and earthquake technology, but it is difficult and
time-consuming for regulation. In order to understand the nonlinear
dynamic behavior of HPS and reduce the cost when using it, this paper
employs differential transformation method to study the bifurcation
behavior of HPS. The numerical results reveal a complex dynamic
behavior comprising periodic, sub-harmonic, and chaotic responses.
Furthermore, the results reveal the changes which take place in the
dynamic behavior of the HPS as the external torque is increased.
Therefore, the proposed method provides an effective means of
gaining insights into the nonlinear dynamics of horizontal platform
system.
Abstract: The value of emission factor was calculated in the
older type of Diesel engine operating on an engine testing bench and
then compared with the parameters monitored under similar
conditions when the EnviroxTM additive was applied. It has been
found out that the additive based on CeO2 nanoparticles reduces
emission of NOx. The dependencies of NOx emissions on reduced
torque, engine power and revolutions have been observed as well.
Abstract: A novel adaptive fuzzy trajectory tracking algorithm of Stewart platform based motion platform is proposed to compensate path deviation and degradation of controller-s performance due to actuator torque limit. The algorithm can be divided into two parts: the real-time trajectory shaping part and the joint space adaptive fuzzy controller part. For a reference trajectory in task space whenever any of the actuators is saturated, the desired acceleration of the reference trajectory is modified on-line by using dynamic model of motion platform. Meanwhile an additional action with respect to the difference between the nominal and modified trajectories is utilized in the non-saturated region of actuators to reduce the path error. Using modified trajectory as input, the joint space controller incorporates compute torque controller, leg velocity observer and fuzzy disturbance observer with saturation compensation. It can ensure stability and tracking performance of controller in present of external disturbance and position only measurement. Simulation results verify the effectiveness of proposed control scheme.
Abstract: In the upstream we place a piece of ring and rotate
it with 83Hz, 166Hz, 333Hz,and 666H to find the effect of the
periodic distortion.In the experiment this type of the perturbation
will not allow since the mechanical failure of any parts of the
equipment in the upstream will destroy the blade system. This type of
study will be only possible by CFD. We use two pumps NS32
(ENSAM) and three blades pump (Tamagawa Univ). The benchmark
computations were performed without perturbation parts, and confirm
the computational results well agreement in head-flow rate. We
obtained the pressure fluctuation growth rate that is representing the
global instability of the turbo-system. The fluctuating torque
components were 0.01Nm(5000rpm), 0.1Nm(10000rmp),
0.04Nm(20000rmp), 0.15Nm( 40000rmp) respectively. Only for
10000rpm(166Hz) the output toque was random, and it implies that it
creates unsteady flow by separations on the blades, and will reduce the
pressure loss significantly
Abstract: This study presents a novel means of designing a simple and effective torque controller for Permanent Magnet Synchronous Motor (PMSM). The overall stability of the system is shown using Lyapunov technique. The Lyapunov functions used contain a term penalizing the integral of the tracking error, enhancing the stability. The tracking error is shown to be globally uniformly bounded. Simulation results are presented to show the effectiveness of the approach.
Abstract: This paper presents the design, analysis and
development of permanent magnet (PM) torque couplers. These
couplers employ rare-earth magnets. Based on finite element analysis
and earlier analytical works both concentric and face-type
synchronous type couplers have been designed and fabricated. The
experimental performance has good correlation with finite element
calculations.
Abstract: Real-time measurement of applied forces, like tension, compression, torsion, and bending moment, identifies the transferred energies being applied to the bottomhole assembly (BHA). These forces are highly detrimental to measurement/logging-while-drilling tools and downhole equipment. Real-time measurement of the dynamic downhole behavior, including weight, torque, bending on bit, and vibration, establishes a real-time feedback loop between the downhole drilling system and drilling team at the surface. This paper describes the numerical analysis of the strain data acquired by the measurement tool at different locations on the strain pockets. The strain values obtained by FEA for various loading conditions (tension, compression, torque, and bending moment) are compared against experimental results obtained from an identical experimental setup. Numerical analyses results agree with experimental data within 8% and, therefore, substantiate and validate the FEA model. This FEA model can be used to analyze the combined loading conditions that reflect the actual drilling environment.
Abstract: The common practice of operating S-rotor is in an
open environment; however there are times when the rotor is
installed in a bounded environment and there might be changes in the
performance of the rotor. This paper presents the changes in the
performance of S-rotor when operated in bounded flows. The
investigation was conducted experimentally to compare the
performance of the rotors in bounded environment against open
environment. Three different rotors models were designed, fabricated
and subjected to experimental measurements. All of the three models
were having 600 mm height and 300 mm Diameter. They were tested
in three different flow environments; namely: partially bounded
environment, fully bounded environment and open environment.
Rotors were found to have better starting up capabilities when
operated in bounded environment. Apart from that, all rotors manage
to achieve higher Power and Torque Coefficients at a higher Tip
Speed Ratio as compared to the open environment.
Abstract: This paper deals with the problem of non-uniform
torsion in thin-walled elastic beams with asymmetric cross-section,
removing the basic concept of a fixed center of twist, necessary in the
Vlasov-s and Benscoter-s theories to obtain a warping stress field
equivalent to zero. In this new torsion/flexure theory, despite of the
classical ones, the warping function will punctually satisfy the first
indefinite equilibrium equation along the beam axis and it wont- be
necessary to introduce the classical congruence condition, to take into
account the effect of the beam restraints. The solution, based on the
Fourier development of the displacement field, is obtained assuming
that the applied external torque is constant along the beam axis and
on both beam ends the unit twist angle and the warping axial
displacement functions are totally restrained.
Finally, in order to verify the feasibility of the proposed method
and to compare it with the classical theories, two applications are
carried out. The first one, relative to an open profile, is necessary to
test the numerical method adopted to find the solution; the second
one, instead, is relative to a simplified containership section,
considered as full restrained in correspondence of two adjacent
transverse bulkheads.
Abstract: The paper is concerned with the state examination as
well as the problems during the post surgical (orthopedic)
rehabilitation of the knee and ankle joint. An observation of the
current appliances for a passive rehabilitation devices is presented.
The major necessary and basic features of the intelligent
rehabilitation devices are considered. An approach for a new
intelligent appliance is suggested. The main advantages of the device
are: both active as well as passive rehabilitation of the patient based
on the human - patient reactions and a real time feedback. The basic
components: controller; electrical motor; encoder, force – torque
sensor are discussed in details. The main modes of operation of the
device are considered.
Abstract: Adaptive observers used in sensorless control of induction motors suffer from instability especally in regenerating mode. In this paper, an optimal feed back gain design is proposed, it can reduce the instability region in the torque speed plane .
Abstract: This paper describes the design and modeling
procedure of a novel 5-phase segment type switched reluctance motor
(ST-SRM) under simultaneous two-phase (bipolar) excitation of
windings. The rotor cores of ST-SRM are embedded in an aluminum
block as well as to improve the performance characteristics. The
magnetic circuit of the produced ST-SRM is constructed so that the
magnetic flux paths are short and exclusive to each phase, thereby
minimizing the commutation switching and eddy current losses in the
laminations. The design and simulation principles presented apply
primarily to conventional SRM and ST-SRM. It is proved that the
novel 5-phase switched reluctance motor under two-phase excitation
is superior among the criteria used in comparison. The purposed
model is particularly well suited for high torque and weight
constrained applications such as automobiles, aerospace and military
applications.
Abstract: This paper is proposed the dynamic simulation of
small power induction motor based on Mathematical modeling. The
dynamic simulation is one of the key steps in the validation of the
design process of the motor drive systems and it is needed for
eliminating inadvertent design mistakes and the resulting error in the
prototype construction and testing. This paper demonstrates the
simulation of steady-state performance of induction motor by
MATLAB Program Three phase 3 hp induction motor is modeled
and simulated with SIMULINK model.
Abstract: In this paper, a direct torque control - space vector
modulation (DTC-SVM) scheme is presented for a six-phase speed
and voltage sensorless induction motor (IM) drive. The decoupled
torque and stator flux control is achieved based on IM stator flux field orientation. The rotor speed is detected by on-line estimating of
the rotor angular slip speed and stator vector flux speed. In addition, a simple method is introduced to estimate the stator resistance.
Moreover in this control scheme the voltage sensors are eliminated
and actual motor phase voltages are approximated by using PWM
inverter switching times and the dc link voltage. Finally, some simulation and experimental results are presented to verify the
effectiveness and capability of the proposed control scheme.