G. Yuan
Volume 5, Issue 4 , December 2008, , Pages 161-166
Abstract
The dynamic characteristics of deflectable nose missiles with rotary single-channel control were investigated in this paper. Firstly, the effective angle of attack, effective angle of sideslip and quasi-body coordinates were introduced based on the spin characteristics of the missile’s body. Secondly, ...
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The dynamic characteristics of deflectable nose missiles with rotary single-channel control were investigated in this paper. Firstly, the effective angle of attack, effective angle of sideslip and quasi-body coordinates were introduced based on the spin characteristics of the missile’s body. Secondly, considering the interaction between the missile’s nose and body, the rigid kinetic model of missile with deflectable nose control was set up in the quasi-body coordinates utilizing rootless multi-rigid-body system dynamics. Finally, computer simulation was performed to investigate and analyze the interaction between the missile’s nose and body. Academic analysis and simulation results indicate that the nose deflection will cause a motion of body on the opposite direction, and the kinetic model established in this paper is correct and reasonable.
M.J. Maghrebi
Volume 3, Issue 4 , December 2006, , Pages 177-183
M.R. Salimi; M. Taeibi Rahni; Mahdi Ramezanizadeh
Volume 9, Issue 1 , March 2012
Abstract
A new design concept is introduced to control the near-wall integration between the hot-gas boundary layer and the cooling jets in order to enhance the adiabatic film cooling effectiveness of the gas turbine blades. In this new approach, another film cooling port, having a very low blowing ratio, which ...
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A new design concept is introduced to control the near-wall integration between the hot-gas boundary layer and the cooling jets in order to enhance the adiabatic film cooling effectiveness of the gas turbine blades. In this new approach, another film cooling port, having a very low blowing ratio, which prevents formation of the counter-rotating vortex pare, is applied just upstream of the main film cooling jet. The fluid injected from the small upstream port changes the flow pattern, resultsinwider horseshoe vortices in the span-wise direction, and generates a more uniform distribution of the coolant film. Also, this coolant fluid flows towards the low pressure region located just behind the main film-cooling hole. Therefore, by producing a cold layer of gas beneath the coolant jet and diverting the hot cross-flow gases into this area, it significantly improves the film cooling effectiveness, especially in the near field of the main jet. The obtained results show lower stream-wise velocity gradients near the wall, which considerably decreases the wall shear stresses, comparing to the regular film cooling holes.
فرید شاهمیری
Volume 10, Issue 1 , March 2013
Abstract
This paper is concerned with the statistical model development issues, necessary for rapid estimation of the rotor sizing for single main rotor helicopters at the preliminary design stage. However, Central Composite Design (CCD) method, simulation-based data collection, linear regression analysis, mathematical ...
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This paper is concerned with the statistical model development issues, necessary for rapid estimation of the rotor sizing for single main rotor helicopters at the preliminary design stage. However, Central Composite Design (CCD) method, simulation-based data collection, linear regression analysis, mathematical modelsdevelopmentand validations through the analysis of variance (ANOVA) were performed as central themes in this approach. The CCD enforced the use of replicated central points and some star points, added to the basic factorial design space, required for constructing the test plan matrix. This matrixwas used to developed mathematical models in the form of quadratic polynomials (second-order), that represented the physical size of rotor as functions of the helicopter gross weight, maximum forward flight speed, main and tail rotor blade number and their interactions.The validations were examined by ANOVA and comparing against data for a general single rotor configuration. Using this approach, improvements in physical sizing of both main and tail rotor of the single rotor were obtained using minimum number of data, provided by CCD test plan.The obtained results of this work support the ongoing researches for the development of rapid prototyping, especially, main and tail rotor sizing of helicopters.
M. Kiani
Volume 10, Issue 2 , September 2013
Abstract
Three-axis-magnetometers (TAMs) are widely utilized as a key component of attitude determination subsystems and as such are considered the corner stone of navigation for low Earth orbiting (LEO) space systems. Precise geomagnetic-based navigation demands accurate calibration of the magnetometers. In ...
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Three-axis-magnetometers (TAMs) are widely utilized as a key component of attitude determination subsystems and as such are considered the corner stone of navigation for low Earth orbiting (LEO) space systems. Precise geomagnetic-based navigation demands accurate calibration of the magnetometers. In this regard, a complete online calibration process of TAM is developed in the current research that considers the combined effects of environmental and instrumental errors including biases, non-orthogonally parameters ,and the scale factors, without the need for clean room facilities. The sensor characteristics are estimated utilizing Kalman filter for a micro electro-mechanical sensor(MEMS)-based TAM standing on the experimental measured outputs in a noisy laboratory environment. Moreover, the stochastic TAM behavior is identified using the method of Allan variance analysis (AVA) through a six-hour static test. Subsequently, the nonlinear/non-Gaussian problem of attitude estimation, using a set of calibrated strap-down magnetometers is addressed utilizing the unscented particle filter (UPF), developed for the removal of colored-noise. Comparison of the estimated attitude, represented by quaternion parameters, with the true orientations demonstrates an acceptable level of accuracy of the developed calibration technique for small LEO space systems. Analysis of the root mean square error of the estimated attitude illustrates an accuracy of less than one degree for all axes. This is an ideal result, given the fact that MEMS-based magnetometers have been utilized.
M. Malekzadeh
Volume 11, Issue 1 , June 2017
Abstract
In this article, the issue of attitude control and active vibration suppression of a nonlinear flexible spacecraft is assessed through piezoelectric patches as actuator and sensors. Two controller loops are applied: the inner loop, to make the panel vibration damped through piezoelectric patches; and ...
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In this article, the issue of attitude control and active vibration suppression of a nonlinear flexible spacecraft is assessed through piezoelectric patches as actuator and sensors. Two controller loops are applied: the inner loop, to make the panel vibration damped through piezoelectric patches; and the outer loop, to perform spacecraft maneuver using the reaction wheel acting on the hub. An optimal controller is designed in the inner loop and two robust controllers are designed as the outer loop, which are used interchangeably. One is a high-ordersliding mode controller using super twisting algorithm and the other is a nonsingular terminal sliding mode controller. With respect to the non-minimum phase properties of the system, if the panel deflection is defined as the output, the output redefinition approach is introduced.The performances of the proposed controllers are compared in terms of tracking attitude trajectory, panel vibration suppression, robustness towards uncertainties, sensor noise, disturbances and nonlinearity in large maneuvers.
Aerospace Science and Technology
Hamid reza Ali mohamadi; Hassan Naseh; Fathollah Ommi
Abstract
The present paper strives for optimization of the Liquid-Propellant Engine (LPE)’s feed system. To this end, the new hybrid meta-model methodology by utilizing the Design of Experiment (DOE) method and the Response Surface Method (RSM) were developed and implemented as two effective means of designing, ...
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The present paper strives for optimization of the Liquid-Propellant Engine (LPE)’s feed system. To this end, the new hybrid meta-model methodology by utilizing the Design of Experiment (DOE) method and the Response Surface Method (RSM) were developed and implemented as two effective means of designing, analyzing and optimizing. The input design variables, constraints, objective function, and their surfaces were identified. Then, the design and development strategy was clarified by utilizing the combination of RSM, DOE and regression analysis. Hence, 64 different experiments were carried out on the RD-253 propulsion system. The response surface curves were drawn and the related objective function equation was obtained. The Analysis of Variance (ANOVA) results indicate that, the developed hybrid model is capable to predict the responses adequately within the limits of input parameters. In addition, the precision of the model was assessed by comparing with the existing samples and the output was interpreted and analyzed that shown highly accuracy. Therefore, desirability function analysis has been applied to LPE’s feed system for achieving to maximize the power and minimize the weight, simultaneously. Finally, confirmatory tests have been conducted with the optimum parametric conditions to validate the optimization techniques. In conclusion, the methodology capability is to optimize the LPE system, an 11% increase in the power to feed system weight ratio and a 2% increase the thrust to engine weight ratio. These values are considerably large for LPE design.
Mohammad Reza Dr. Soltani
Volume 2, Issue 1 , March 2005, , Pages 15-19
Goodarz Ahmadi
Volume 1, Issue 1 , October 2004, , Pages 17-22
Abstract
An overview of removal and re-entrainment of particles in turbulent flows is presented. The procedure for the direct numerical simulation (DNS) of the Navier-Stokes equation via a pseudospectral method for simulating the instantaneous fluid velocity field is described. Particle removal mechanisms in ...
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An overview of removal and re-entrainment of particles in turbulent flows is presented. The procedure for the direct numerical simulation (DNS) of the Navier-Stokes equation via a pseudospectral method for simulating the instantaneous fluid velocity field is described. Particle removal mechanisms in turbulent flows in a duct are examined and effects of the near-wall coherent eddies on the particle detachment and removal are discussed. The particle equation of motion, including the hydrodynamic drag and lift, as well as the Brownian and gravitational forces, are used in the analysis. The simulation results show that large size particles move away roughly perpendicular to the wall due to the action of the shear lift force. Small particles, however, follow the upward flows formed by the near wall eddies in the low speed streak regions. Thus, turbulent near wall eddies play an important role in small particle resuspension, while the lift force is an important factor for re-entrainment of large particles. The results also suggest that small particles primarily move away from the wall in the low speed streaks, while larger particles are mostly removed in the high-speed streaks.
o. Abouali
Volume 4, Issue 1 , March 2007, , Pages 17-23
Abstract
In this study, the results of parallelization of a 3-D dual code (Thin Layer, Parabolized Navier-Stokes solver) for solving supersonic turbulent flow around body and wing-body combinations are presented. As a serial code, TLNS solver is very time consuming and takes a large part of memory due to the ...
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In this study, the results of parallelization of a 3-D dual code (Thin Layer, Parabolized Navier-Stokes solver) for solving supersonic turbulent flow around body and wing-body combinations are presented. As a serial code, TLNS solver is very time consuming and takes a large part of memory due to the iterative and lengthy computations. Also for complicated geometries, an exceeding number of grid points are required that results in larger serial computation times. Therefore parallelizing this code would bring about a large saving in computer time and memory. In this study, a cluster of 16 computational nodes with 2.4 and 2.8 GHz, P4 CPU has been used. Also MPI library is used for communicating data among processors. Domain is partitioned in a 1-D form in longitudinal, radial and circumferential directions and results are compared with those of serial computations. There are several methods for data communication among processors such as blocking send and non-blocking send. The performance of each method is evaluated and the best method for the problem at hand is determined. The results are compared in terms of run time, speed-up and efficiency for executing the parallel code on 1, 2, 3, 4, 8, 12 and 16 processors. Also the parallel results are compared with serial results and the correctness of the parallel code is proved for each case. The effect of different partitioning direction and their interaction with the turbulence modeling is studied and the best choice is shown. The limitations of using Baldwin-Lomax turbulence model in a parallel program are discussed and a remedy is presented.
Ali Reza Nadri; Hamid Reza ُShidvash
Abstract
The vacuum test stand simulates the space systems' engines with a high expansion ratio at high altitudes and vacuum pressure for static tests. This article investigates the flow stability in the diffuser to use in a vacuum stand. Several variables are essential in the operation of this system, including ...
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The vacuum test stand simulates the space systems' engines with a high expansion ratio at high altitudes and vacuum pressure for static tests. This article investigates the flow stability in the diffuser to use in a vacuum stand. Several variables are essential in the operation of this system, including the diffuser length, the location of the nozzle relative to the diffuser, the dimensions of the vacuum chamber, and the diffuser length-to-diameter ratio. In this numerical study, the diffuser length-to-diameter ratio is investigated applied at different pressures by the rocket engine to the stand. These results are performed in three length-to-diameter ratios of 6, 8, and 10, and the applied pressure varies from 30 to 50 bar. With an increase in the geometric ratio of diffuser length-to-diameter, stable conditions can be created in the diffuser at lower applied pressures.
I. Babaeian
Volume 2, Issue 2 , June 2005, , Pages 19-27
Mohammad Zaman Kabir
Volume 2, Issue 3 , September 2005, , Pages 19-27
Abstract
This study investigates geometrical non-linear analysis of composite circular cylindrical shells under external pressure over part of their surfaces and also shells subjected to combined axial compression and triangular external pressure. Donnell non-linear shell theory along with first order shear deformation ...
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This study investigates geometrical non-linear analysis of composite circular cylindrical shells under external pressure over part of their surfaces and also shells subjected to combined axial compression and triangular external pressure. Donnell non-linear shell theory along with first order shear deformation theory (FOSD) are adopted in the analysis. In the case of combined axial compression and triangular external pressure post-buckling curves for various shell stacking sequences and different load interaction parameter are traced. Comparison of the results for uniform and triangular external pressures in combination with axial compression applied to the laminated cylindrical shells is carried out in terms of interaction buckling curves and load-deflection and load-shortening diagrams.
Mehdi Sharifyazdi
Volume 4, Issue 4 , December 2007, , Pages 19-27
Abstract
To formulate a single-leg seat inventory control problem in an airline ticket sales system, the concept and techniques of revenue management are applied in this research. In this model, it is assumed the cabin capacity is stochastic and hence its exact size cannot be forecasted in advance, at the time ...
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To formulate a single-leg seat inventory control problem in an airline ticket sales system, the concept and techniques of revenue management are applied in this research. In this model, it is assumed the cabin capacity is stochastic and hence its exact size cannot be forecasted in advance, at the time of planning. There are two groups of early-reserving and late-purchasing customers demanding this capacity. The price rate as well as the penalty for booking cancellation caused by overbooking is different for each group. The model is developed mathematically and we propose an analytical solution method. The properties of the optimal solution as well as the behavior of objective function are also analyzed. The objective function is neither concave nor convex in general. However, we prove it is a unimodal function and by taking advantage of this property, the optimal solution is determined.
Yazdan Amerian; ????? ????? ???????; B. Voosoghi; Ali Ghaffari
Volume 7, Issue 1 , March 2010, , Pages 19-29
Abstract
Ionospheric tomography is a method to investigate the ionospheric electron density in two or three dimensions. In this study, the function-based tomographic technique has been used for regional reconstruction of a 3D tomographic model of the ionospheric electron density using the GPS measurements of ...
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Ionospheric tomography is a method to investigate the ionospheric electron density in two or three dimensions. In this study, the function-based tomographic technique has been used for regional reconstruction of a 3D tomographic model of the ionospheric electron density using the GPS measurements of the Iranian Permanent GPS Network. Two-dimensional Haar wavelets and empirical orthogonal functions are used as base functions to model the horizontal and the vertical structure of the electron density, respectively. Sparseness of data and data gaps make ionospheric tomography an ill-posed inverse problem. The truncated singular value decomposition (TSVD) method is used to come up with solution. The data analysis results show that the latitudinal sections of the electron density in ionosphere obtained from the tomographic technique supports the expected time and height variations in the electron density. Moreover, these findings show that the height of maximum electron density is changed during the day. This confirms the efficiency of the developed multilayer model in comparison to the traditional single-layer ones. The relative error between the reconstructed electron density and the electron density obtained from ionosonde data varies between 5 to 35 percent. The difference between the reconstructed electron density (as well as the corresponding estimations of the IRI-2001 model) and the direct estimates of this quantity increases when the electron density reaches to its maximum value. Assuming that the ionosonde station in Tehran produces reliable results, this proves that the reconstructed image as well as the IRI-2001 model does not efficiently constraint the electron density during this period of time.
Aerospace Science and Technology
Ehasan Zibaei; Mohammad-Ali Amiri Atashgah; Ahmad Kalhor
Volume 12, Issue 2 , October 2019, , Pages 19-33
Abstract
This paper presents a tuned behavior-based guidance algorithm for formation flight of quadrotors. The behavior-based approach provides the basis for the simultaneous realization of different behaviors such as leader following and obstacle avoidance for a group of agents; in our case they are quadcopters. ...
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This paper presents a tuned behavior-based guidance algorithm for formation flight of quadrotors. The behavior-based approach provides the basis for the simultaneous realization of different behaviors such as leader following and obstacle avoidance for a group of agents; in our case they are quadcopters. In this paper optimization techniques are utilized to tune the parameters of a behavior-based guidance algorithm; to compromise between safety, trajectory optimality, and control effort during the formation flight. The tuning is formulated as a constraint optimization problem where the penalty function method is used to secure the safe passage of quadrotors around an obstacle. The guidance subsystem is integrated with a consistent dynamic inversion controller to realize a smooth maneuver of the quadrotors along desired trajectories. For more, MATLAB/Simulink is used as the programming platform. The effectiveness of the tuning method is verified, based on the performance of the closed-loop system in the presence of an overall navigation system uncertainties and actuator lags.
Aerospace Science and Technology
Mahdi Fakoor; Hamidreza Heidari; Behzad Moshiri; Amir reza Kosari
Abstract
In this study, Adaptive Network-Based Fuzzy Inference System (ANFIS) is presented with sensor data fusion approach to estimate satellite attitude. The active sensors are sun and earth sensors. Satellite attitude dynamic, including attitude quaternion and angular velocities are estimated simultaneously ...
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In this study, Adaptive Network-Based Fuzzy Inference System (ANFIS) is presented with sensor data fusion approach to estimate satellite attitude. The active sensors are sun and earth sensors. Satellite attitude dynamic, including attitude quaternion and angular velocities are estimated simultaneously utilizing the measured values by the sensors. The Extended Kalman Filter (EKF) is employed to verify and evaluate the efficiency of the presented method. Additionally, the neural networks with Radial Basis Function (RBF) and Multi-Layer Perceptron (MLP) are also designed to prove the superiority of the proposed ANFIS network among the smart methods of sensor data fusion for satellite attitude estimation. Root Mean Square Error (RMSE) as a numerical criterion and graphical analysis of residues are utilized to evaluate the simulation results. The simulations confirm that the obtained estimations from ANFIS network have more accuracy in modeling of nonlinear complex systems compared to EKF, MLP and RBF networks. In general, using intelligent data fusion, especially ANFIS, reduces attitude estimation error and time in comparison to the classical EKF method.
N. Fazli; S. Moammad Bag Malaek; Ali Abedian
Volume 8, Issue 1 , March 2011, , Pages 21-28
Abstract
Here, we present a novel two-step approach for optimum design of cellular truss-beams based on desired natural frequencies. The proposed approach at- tempts to decrease the design complexities, based on the so called Axiomatic Design, before any e ort to solve the physical problem itself. It also serves ...
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Here, we present a novel two-step approach for optimum design of cellular truss-beams based on desired natural frequencies. The proposed approach at- tempts to decrease the design complexities, based on the so called Axiomatic Design, before any e ort to solve the physical problem itself. It also serves as a generic approach which nds its generality through dimensional analysis with its accuracy from nite element analysis and its optimality from the fact that it remains true for all similar frameworks. The applicability as well as strength of the method is highlighted by some numerical examples.
Hassan Karimi; Amir Nassirharand
Volume 3, Issue 1 , March 2006, , Pages 23-30
Abstract
In this paper application of a simulation algorithm for dynamic and nonlinear analysis of a specific liquid propellant engine is presented. The mathematical model of the engine includes a set of nonlinear algebraic equations which is coupled with a set of time varying differential equations. In contrast ...
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In this paper application of a simulation algorithm for dynamic and nonlinear analysis of a specific liquid propellant engine is presented. The mathematical model of the engine includes a set of nonlinear algebraic equations which is coupled with a set of time varying differential equations. In contrast to the existing liquid propellant simulation algorithms, the presented work does not depend on the method of modeling. The simulation algorithm is composed of six primary steps. Comparison of the nominal values obtained from simulation with actual designed values is presented. Typical simulation outputs of primary engine variables are also given. The results of this study are used in the initial and conceptual design stages in order to advance to the other design stages.
Soheila Javanmard; J. Bodagh jamali
Volume 4, Issue 2 , June 2007, , Pages 23-31
Mohammad Pasandidefard Fard
Volume 5, Issue 1 , March 2008, , Pages 23-33
Abstract
A computational study of partial cavitation over axisymmetric bodies is presented using two numerical methods. The first method is based on the VOF technique where transient 2D Navier-Stokes equations are solved along with an equation to track the cavity interface. Next, the steady boundary element method ...
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A computational study of partial cavitation over axisymmetric bodies is presented using two numerical methods. The first method is based on the VOF technique where transient 2D Navier-Stokes equations are solved along with an equation to track the cavity interface. Next, the steady boundary element method (BEM) based on potential flow theory is presented. The results of the two methods for a disk cavitator are compared with each other and with those of the available experiments and analytical relations. The two methods are then used to predict the partial cavity over an axisymmetric body consisting of a disk cavitator followed by a conical section and ending in a cylindrical shape. The effects of various parameters such as cone length, cone angle, cavitator radius and cylinder diameter are investigated. The results show that as the cone length is increased, the cavity region covers a larger portion of the body. Reducing the cone angle increases both the length and diameter of the cavity region. For an axisymmetric body with a larger radius the cavity detachment is more likely to occur.
S. M. Hoseini
Volume 11, Issue 2 , October 2017, , Pages 23-32
Abstract
Conventional quaternion based methods have been extensively employed for spacecraft attitude control where the aerodynamic forces can be neglected. In the presence of aerodynamic forces, the flight attitude control is more complicated due to aerodynamic moments and inertia uncertainties. In this paper, ...
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Conventional quaternion based methods have been extensively employed for spacecraft attitude control where the aerodynamic forces can be neglected. In the presence of aerodynamic forces, the flight attitude control is more complicated due to aerodynamic moments and inertia uncertainties. In this paper, a robust nero-adaptive quaternion controller based on back-stepping technique for vehicle with aerodynamic actuators is proposed. The presented control lawconsists of a neural network based adaptive part and an additional term which ensures the robustness of the system. Actually, the first term is designed to approximate and cancel out the matched uncertainties and the second term is used toensure the robustness of system against approximation error of the neural network.The Lyapunov direct method is applied to derive the learning laws for the neural network weights and adaptive gain. Also,theultimately boundedness of the error signals is guaranteed based on theLyapunov’s stability criterion. The benefit of the presented method is evaluated through simulation of an aerodynamic control vehicle.
Aerospace Science and Technology
Seyyed Reza Ghaffari-Razin; Reza Davari-Majd; Behzad Voosoghi; Navid Hooshangi
Abstract
Computerized Ionospheric Tomography (CIT) is a method to reconstruct ionospheric electron density image by computing Total Electron Content (TEC) values from the recorded GPS signals. Due to the poor spatial distribution of GPS stations, limitations of signal viewing angle and discontinuity of observations ...
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Computerized Ionospheric Tomography (CIT) is a method to reconstruct ionospheric electron density image by computing Total Electron Content (TEC) values from the recorded GPS signals. Due to the poor spatial distribution of GPS stations, limitations of signal viewing angle and discontinuity of observations in time and space domain, CIT are an inverse ill-posed problem. In order to solve these problems, two new methods are developed and compared with the initial method of Residual Minimization Training Neural Network (RMTNN). Modified RMTNN (MRMTNN) and Ionospheric Tomography based on the Neural Network (ITNN) is considered as new methods of CIT. In all two methods, Empirical Orthogonal Functions (EOFs) are used to improve accuracy of vertical domain. Also, Back Propagation (BP) and Particle Swarm Optimization (PSO) algorithms are used to train the neural networks. To apply the methods for constructing a 3D-image of the electron density, 23 GPS measurements of the International GNSS Service (IGS) with different geomagnetic indexes are used. For validate and better assess reliability of the proposed methods, 4 ionosondee stations have been used. Also the results of proposed methods have been compared to that of the NeQuick empirical ionosphere model. Based on the analysis and comparisons, the RMSE of the ITNN model at high geomagnetic activity in DOUR, JULI, PRUH and WARS ionsonde stations are 1.22, 1.46, 1.18 and 1.19 (1011 ele./m3), respectively. The results show that RMSE of the ITNN model is less than other models in both high and low geomagnetic activities and in ionosonde stations.
Rahmatollah Ghajar; G. R. Rashed
Volume 4, Issue 3 , September 2007, , Pages 25-35
Abstract
Engineers have a range of methods to estimate the fatigue life under multiaxial conditions. Each of these predictive methods is generally subjected to restrictions, related to the inherent simplified assumptions. The objective of this paper is to evaluate the validity of commonly used multiaxial fatigue ...
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Engineers have a range of methods to estimate the fatigue life under multiaxial conditions. Each of these predictive methods is generally subjected to restrictions, related to the inherent simplified assumptions. The objective of this paper is to evaluate the validity of commonly used multiaxial fatigue criteria for different multiaxial loading conditions. The best criterion is identified through comparative analysis. The assessment is based on the experimental research findings of the SAE notched shaft, which is used as a benchmark [1]. The relative performance of three of existing multiaxial fatigue theories based on the strain criteria and the critical plane approaches are investigated. There is not any fixed strain life criterion that can predict the fatigue life best for different loading. Among all the critical plane models considered, Fatemi and Socie model [2] gives best fatigue life prediction for both multiaxial in phase and 90° out of phase loading cases.
A. Davari; M. Hadi Dulabi; Mohammad Reza Dr. Soltani; F. asakari
Volume 6, Issue 1 , March 2009, , Pages 25-35
Abstract
An experimental study was performed to investigate the effects of the body angle of attack on the tail surface pressure distribution for a half body-tail combination in subsonic flow. The results show, in small deflection angle regions, that the tail deflection has the same effect on the surface pressure ...
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An experimental study was performed to investigate the effects of the body angle of attack on the tail surface pressure distribution for a half body-tail combination in subsonic flow. The results show, in small deflection angle regions, that the tail deflection has the same effect on the surface pressure as the body angle of attack. However at moderate to high deflections, the flowfiled caused by the tail deflection angle is completely different from that of the body angle of attack, which is an indication of the nose and body vortex shedding effects on the tail at high angle of attack regime.
