Desain dan Pengembangan Sistem Kecerdasan Robotika Muatan Roket dengan 5 Derajat Kebebasan dengan Kontrol Sistem Pendaratan Navigasi X-Y Kartesian

In this study a design and manufacture a rocket payload system that has the ability to fly autonomously intelligently is discussed. The rocket payload system was designed to be able to return to the landing position. This system consists of two sub systems, namely rocket payload and host computer (ground segment). A robotic-based rocket payload has a CPU-based system controller with a specific I/O for sensor-actuator is equipped with a set of telemetry systems. The I/O data can be sent to the host computer at the ground segment. Host computer with the ground segment is a useful tool to receive data from a rocket payload telemetry or navigation data which is then processed by a computer in the form of tables, graphs and map navigation. Direction control systems used for rocket payload system is fuzzy logic control with the input of compass and GPS data and the output scale propeller actuation to the system used by rocket payload. Testing of control systems was conducted in laboratory scale. Input is data of the desired setpoint with output in PWM DC Motor form to stabilize the rocket payload. The test results obtained for this direction control system to minimize the ∆error value of the set point desired direction so that the error is almost close to zer

DESAIN DAN SISTEM PENGENDALIAN PELUNCUR ROKET CERDAS BERDASARKAN KECEPATAN DAN ARAH ANGIN

At this final task will be analyzed and implementated position control using PID (Proportional, Integratif and Derivative) controller in a plant of two degree-of-freedom Rocket Launcer with joint-Launcer configuration controlled by two DC motor. Movement input of rocket launcer will be controlled by a Mikrocontroler using C program and Matlab Simulink application. The input has given by the form of target position and PID constanta. Controling the rocket launcer use the DC motor which calculated movement direction and regardless dynamic motor constanta. This implementation process border with special purpose of rocket launcher two degrees freedom is designed to be able to perform the specific function rise-down movement and rotates up to 360 degrees. Rocket launcher equipped with sensor enviromment wind velocity and direction to make rocket launchers that could see the wind direction changes so that know where the rocket launching at the right time. Sensor enviromment wind velocity and direction will be used as input to the system for the value of PID control parameters. Data collected from wind speed and direction sensors enviromment as an input is obtained that changes in a degree equal to 2,44. the results are expected to value the PID control parameters that can be used to design a rocket launcher system with a more complex system with feedback purposes

A Technique For Lock-In Prediction On A Fluid Structure Interaction Of Naca 0012 Foil With High Re

A numerical lock-in prediction technique of a NACA 0012 hydrofoil, immersed in a flow having a Re of 3.07x106 is proposed in this paper. The technique observes the foil’s response as part of a fluid-structure interaction analysis. The response is modelled by foil’s vibration which is represented by spring and damper components. The technique identifies and predicts the foil’s lock-in when it vibrates. The prediction is examined using the Phase Averaged Method which employs the Hilbert Transform Method. The aim of this paper is to propose a numerical way to identify a lock-in condition experienced by a NACA 0012 foil in a high Reynolds number flow. The foil’s mechanical properties are selected and its motions are restricted in two modes which are in the pitch and heave directions. The rotational and transverse lock-in modes are identified in the model. The existence of lock-in is verified using pressure distribution plot, the history of trailing edge displacement and fluid regime capture. The history of total force coefficients is also shown to justify the result. The result shows that the technique can predict reliably the lock-in condition on the foil’s interaction. Three main fluid induced vibration frequencies are generated in the interaction. None of them are close to natural frequency of the foil and lock-in is apparently not found in the typical operational condition

The Development of A Reliability Evaluation Application for Power Plant Steam Turbine Vibrations to Predict Its Failure

A steam turbine is the most critical component in a thermal power plant. Due to its crucial function, it should be maintained to be able to operate without failure. This paper aims to develop an application that can be used to analyze the reliability and synchronization of vibrations in a single evaluation through the application. The application is helpful to decide the proper time the maintenance should be performed in order to provide a better maintenance strategy. In this paper, the application was used to make an ease in evaluating the reliability and vibration of a 670 MW power plant steam turbine. The reliability was analyzed by qualitative and quantitative methods. The vibration evaluation using Fast Fourier Transform (FFT) was done by diagnosing the failure symptoms from vibration spectrum. The analysis of synchronization of vibrations conducted by comparing the vibration frequency and the natural frequency of the system which can be calculated easily using the application. The algorithm program of both evaluations was built using GNU Octave software to make a friendly user interface. From the evaluation result, the most critical components of the steam turbine are coupling, labyrinth seals, bearing, diaphragm, turbine control valve, and turbine stop valve. The maintenance interval based on the expected reliability of 90% produces the highest reliability improvement. Based on the vibration analysis, there is no failure symptoms detected in the turbine bearings. Furthermore, the dominant frequencies of vibration are distant from the natural frequency. Therefore, the steam turbine condition is acceptable to operate

Numerical Analysis of Wave Load Characteristics on Jack-Up Production Platform Structure Using Modified k-ω SST Turbulence Model

One of the important stages in the offshore structure design process is the evaluation of the marine hydrodynamic load in which the structure operates, this is to ensure an appropriate design and improve the safety of the structure. Therefore, accurate modeling of the marine environment is needed to produce good evaluation data, one of the methods that can accurately model the marine environment is through the Computational Fluid Dynamic (CFD) method. This research aims to analyze the ocean wave load of pressure and force characteristics on the jack-up production platform hull structure using the (CFD) method. The foam-extend 4.0 (the fork of the OpenFOAM) software with waveFoam solver is utilized to predict the free surface flow phenomena as its capability to predict with accurate results. The Reynold Averaged Navier Stokes (RANS) turbulence model of k-ω SST is applied to predict the turbulence effect in the flow field. Five variations of incident wave direction type are carried out to examine its effect on the pressure and force characteristics on the jack-up production platform hull. The wave model shows inaccurate results with the decrease in wave height caused by excessive turbulence in the water surface area. Excessive turbulence levels can be overcome by incorporating density variable and buoyancy terms based on the Standard Gradient Diffusion Hypothesis (SGDH) into the turbulent kinetic energy equation. The k-ω SST Buoyancy turbulence model shows accurate results when verified to predict wave run-up and horizontal force loads on monopile structures. Furthermore, test results of the wave load on the jack-up production platform hull structure shows that the most significant wave load is obtained in variations with the wave arrival direction relatively opposite to the platform wall. Especially in the direction of 90° because it also has the most expansive impact surface area. Meanwhile, the lower wave load is obtained in variations 45° and 135°, which have the relatively oblique direction of wave arrival to the surface

Numerical Study of a Wind Turbine Blade Modification Using 30° Angle Winglet on Clark Y Foil

The depletion of fossil fuels and the worsening environment motivate engineers and researchers to explore renewable energy resources. One of the promising renewable energy is wind energy. The wind turbine extracts wind energy to generate electricity. This study aims to modify a wind turbine blade using Clark Y foil to improve the lift force. The modification is employed by forming a winglet profile with a 30° angle on the foils tip. The result shows that the 30° winglet enlarges the lift coefficient to 1.3253 from 1.2795 of the original blade lift coefficient.

Analysis of Fluid Flow Characteristics Across the Darrieus Turbine in Irrigation Channels: ANALISA KARAKTERISTIK ALIRAN FLUIDA MELINTASI TURBIN DARRIEUS PADA SALURAN IRIGASI

This study simulated the characteristics of the fluid flow that passes through the Darrieus turbine before installation and testing were carried out. The purpose of knowing the flow characteristics can determine the profile and position of the maximum speed so that the design and placement of the turbine can be improved. The research method was carried out using dynamic fluid computational simulations in three-dimensional form with steady state conditions, discretization using second-order, with convergent conditions when it reached 10-6. The simulation results show that the position of the flow above the turbine had the lowest value because the fluid flowed relatively without disturbance which caused the velocity to had a value almost the same as the incoming fluid velocity. The fluid velocity increased when it was in line 2 and line 3 or across the turbine. This was due to the turbulence generated by the rotation of the turbine. While the speed on line 4 or below the turbine had a lower value than line 2 and line 3. This was due to the position below the turbine so that the turbine rotation did not have an impact on speed. At the four line positions the velocity increased at Y=0.7 m or when the fluid hits the turbine. This increase in fluid velocity was expected to turn the turbine. The results also included the flow distribution in the form of a streamline in several positions where the flow that was in contact with the channel wall had a low velocity value due to friction with the wall

Thermal Analysis of Solar Air Heater with Ventilator Turbine and Fins

Solar air heater (SAH) is a renewable energy application for the drying process. SAH has a challenge to produce high performance under uncertain weather. The performance of SAH can be enhanced by providing the absorber plate by adding the fins. This study aims to evaluate the thermal performance of SAH with rectangular fins SAH at low air velocity. This study compares the performance of SAH without fins and SAH with rectangular fins. Two variations of a tilt angle of SAH are 0° and 30° which are observed in this study. The SAH uses a ventilator turbine to suck air into the collector box. The air velocity is 0.01 m/s. The method is experimental. The SAH is tested under real condition from 9 a.m. to 4 p.m. The measurement tools consist of  a pyranometer, an anemometer, a temperature sensor in the inlet section, 3 sensors in the absorber plate, a sensor in the outlet section,  6 temperature sensors in the drying cabinet. The result showed the thermal efficiency of SAH with rectangular fins is 29.67 % higher than SAH without fins at 0˚ tilt of angle at noon. The thermal efficiency of SAH with rectangular fins is 25.26 % higher than  that of without fins at 30˚ tilt of angle at noon

The influence of trailing edge shape on fluid structure interaction of a vertical axis tidal turbine blade

The depletion of fossil fuel and the increase of fuel consumption globally create an increased demand for the use of renewable energy. Vertical axis tidal turbines are a promising renewable energy device which needs to be improved. One problem appears in its operation is the structural instability and noise coming from the vibration of the long slender vertical axis blades. The vibration is a result of fluid structure interaction between turbine blades and the unsteady tidal current. This interaction of the tides and the blade generates vortical features which can excite the turbine blades to vibrate and causes a tonal noise known as singing. The aim of this work is to predict the blade response and locked-in condition by controlling the vortex shedding. The vortex is controlled by modifying blade’s trailing edge shape. The modifications include truncated, sharp and rounded trailing edge shapes. The response is modeled by vibrations using a spring damper system. A 2D numerical model of a vertical axis tidal turbine blade is developed to resolve the vibration using OpenFOAM 2.2. The blade has 0.75 m chord length and 3.07×106 Re. The model employs the equivalence incoming velocity method which represents the actual unsteady tidal current by time varying velocity magnitude and angle of attack of the model incoming flow. The problem is examined by observing the force applied to a static blade, and a rotating three bladed vertical axis turbine primarily. This is to confirm that the mesh topology and selected boundary conditions are sufficient and robust to resolve the blade response model. The locked-in condition is clarified by the blade main frequencies, pressure distribution, displacement, and force coefficients. In addition to the reference trailing edge, three different trailing edge shapes were studied. From the results it can be seen that the response is sensitive to pitching motion, high blade initial angle of attack, high tidal velocity and low spring and damping constant blade material. The results also show that the blunt (conventional truncated) foil has the largest ability to control the turbine blade response which is demonstrated by the smallest amplitude and the least frequent turbine blade’s vibration. For all three trailing edge shapes, along with a more limited investigation of an asymmetric trailing edge all are shown to be able to shift the frequency of the resonant response. This will allow the designer to study the likely behaviour of their design. Overall, the developed methodology using a two-dimensional, three degree of freedom solution of the unsteady CFD around the foil is shown to provide useful insight to the tidal turbine designer at a reasonable computational cost

The effect of trailing edge profile modifications to fluid-structure Interactions of a vertical axis tidal turbine blade

Renewable energy has become an essential energy alternative since the continual depletion of non-renewable energy resources and increasing environmental issues. Tidal energy is a promising future renewable resource which can be extracted using a vertical axis tidal turbine. Since it was proposed, a tidal turbine performance requires improvements which can be obtained by a blade’s trailing edge modification. Modifying the blade’s trailing edge profile is confirmed to be one way to improve a turbine’s work. However, the influence of a trailing edge modifications on a vertical axis tidal turbine blade’s interaction with fluid has not been fully understood. The fluid behaviour as an interaction response on a vertical axis tidal turbine blade has not been completely discovered. In this paper, 2D fluid-structure interactions of modified vertical axis tidal turbine blades are examined and modelled using Open FOAM. The interaction exhibits fluid induced vibration which is performed by a turbine blade’s displacement during operation. Three different modified blade profiles are proposed: sharp, rounded, and blunt. The modified profiles are employed to an original NACA 0012 blade and their influences on a vertical axis tidal turbine blade interaction are observed. The result discovers the fluid behaviour and fluid-induced vibrations at all positions (represented by 12 positions) over one turbine’s cycle. The results demonstrate the frequency domain blade velocities and time domain blade displacements for all modified blades. The fluid behaviour around the blade is confirmed by pressure distribution plots over the blade’s upper and lower surfaces. The results show that the blunt profile provides less frequent vibrations due to a reducing vorticity in the downstream fluid regime. However, the vibration amplitude that occurs on the blunt blade is higher than those of rounded and sharp profiles. Based on this research, the blunt trailing edge profile appears to be more favourable to be applied and used for vertical axis tidal turbine blades