Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177585
U. Naeem, Z. Jawaid, S. Sadruddin
In this paper two techniques employed for compensating the Doppler shift encountered in LEO satellite receivers are presented. These include the analog compensation technique involving the carrier tracking loop and the compressive receiver technique. The compressive receiver technique which involves precise detection of the rapidly time varying carrier frequency received by the satellite receiver is discussed in further detail. A compressive receiver with a center frequency of 100 kHz and a Doppler shift up to ±100 kHz is simulated on MATLAB to test the technique.
{"title":"Doppler shift compensation techniques for LEO satellite on-board receivers","authors":"U. Naeem, Z. Jawaid, S. Sadruddin","doi":"10.1109/IBCAST.2012.6177585","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177585","url":null,"abstract":"In this paper two techniques employed for compensating the Doppler shift encountered in LEO satellite receivers are presented. These include the analog compensation technique involving the carrier tracking loop and the compressive receiver technique. The compressive receiver technique which involves precise detection of the rapidly time varying carrier frequency received by the satellite receiver is discussed in further detail. A compressive receiver with a center frequency of 100 kHz and a Doppler shift up to ±100 kHz is simulated on MATLAB to test the technique.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"5 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126188559","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177520
A. Zeeshan, N. Nauman, M. Khan
The ball balancing system in a 2-degree of freedom platform is of unique importance in understanding the control system applications. It is a platform to test and identify different aspects of controls, as the non-linearities increases with the degree of freedoms. So far many techniques have been applied to sense the position of the ball on a plate in real time, most common of them is touchpad and audio video camera system. This paper describes the design, development and control strategy of balancing a ball on a plate using low cost phototransistor sensors. These Phototransistors are triggered by monochromatic sharp beams of laser light. The plate area is 1sq. foot and an array of 11 sensors each 1 inch apart is used on each axis making total of 121 points on the plate. To balance the ball, two motors are used one for each axis. The ground motor is fixed, while to control the other axis second motor is fixed on top of the ground motor. Hence the system utilizes two sets of independent control mechanisms, each operating in isolation for each axis. ATMEGA16 microcontroller is used which is an Atmel AVR family controller with a flash memory of 16 kb. Since it has two independently switched PWM channels, therefore, it makes this controller ideal for the purpose. Dynamic modeling of the system yields the digital controller capable of balancing the ball in any of the desired positions out of 121 points, on the plate. Although the system becomes quite discrete but still it provides sufficient basis for implementing different control strategies and investigating different system parameters such as actuation mechanism, sensors, controller design and experimental testing, under the predefined condition of the ball diameter.
{"title":"Design, control and implementation of a ball on plate balancing system","authors":"A. Zeeshan, N. Nauman, M. Khan","doi":"10.1109/IBCAST.2012.6177520","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177520","url":null,"abstract":"The ball balancing system in a 2-degree of freedom platform is of unique importance in understanding the control system applications. It is a platform to test and identify different aspects of controls, as the non-linearities increases with the degree of freedoms. So far many techniques have been applied to sense the position of the ball on a plate in real time, most common of them is touchpad and audio video camera system. This paper describes the design, development and control strategy of balancing a ball on a plate using low cost phototransistor sensors. These Phototransistors are triggered by monochromatic sharp beams of laser light. The plate area is 1sq. foot and an array of 11 sensors each 1 inch apart is used on each axis making total of 121 points on the plate. To balance the ball, two motors are used one for each axis. The ground motor is fixed, while to control the other axis second motor is fixed on top of the ground motor. Hence the system utilizes two sets of independent control mechanisms, each operating in isolation for each axis. ATMEGA16 microcontroller is used which is an Atmel AVR family controller with a flash memory of 16 kb. Since it has two independently switched PWM channels, therefore, it makes this controller ideal for the purpose. Dynamic modeling of the system yields the digital controller capable of balancing the ball in any of the desired positions out of 121 points, on the plate. Although the system becomes quite discrete but still it provides sufficient basis for implementing different control strategies and investigating different system parameters such as actuation mechanism, sensors, controller design and experimental testing, under the predefined condition of the ball diameter.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"12 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"126165384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177521
I. Khan, A. I. Bhatti, Q. Khan, Q. Ahmad
This paper presents various sliding mode techniques starting from a conventional first order SMC and then integral SMC, Super twisting algorithm and real twisting algorithm) for the tracking control of the lateral dynamics of an autonomous underwater vehicle (AUV). Moreover the controllability and observability analysis of the lateral dynamics is given and a Slotine observer [J, -J. E Slotine, J. K Hedrick, E. A. Misawa 1987] has also been proposed for it. Based on the simulation results a comparison of various controllers is made. The higher order SMC provides a chattering free tracking and a model free control which is robust to parametric variations.
从传统的一阶滑模控制到积分滑模控制、超扭转算法和实扭转算法，提出了用于自主水下航行器(AUV)横向动力学跟踪控制的各种滑模技术。此外，给出了横向动力学的可控性和可观测性分析，并给出了一个slotime观测器[J]。E Slotine, J. K . Hedrick, E. A. Misawa 1987]也被提出。在仿真结果的基础上，对各种控制器进行了比较。高阶SMC提供无抖振跟踪和无模型控制，对参数变化具有鲁棒性。
{"title":"Sliding mode control of lateral dynamics of an AUV","authors":"I. Khan, A. I. Bhatti, Q. Khan, Q. Ahmad","doi":"10.1109/IBCAST.2012.6177521","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177521","url":null,"abstract":"This paper presents various sliding mode techniques starting from a conventional first order SMC and then integral SMC, Super twisting algorithm and real twisting algorithm) for the tracking control of the lateral dynamics of an autonomous underwater vehicle (AUV). Moreover the controllability and observability analysis of the lateral dynamics is given and a Slotine observer [J, -J. E Slotine, J. K Hedrick, E. A. Misawa 1987] has also been proposed for it. Based on the simulation results a comparison of various controllers is made. The higher order SMC provides a chattering free tracking and a model free control which is robust to parametric variations.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"297 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"133548431","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177588
H. A. Mirza, I. Shah, F. Abbasi, M. Shafiq
Beamformer is an indispensible part of any phased array system. Analog beamformer is the simpler method where the individual signals received from array of antennas are co-phased and summed to maximize the signal reception. The co-phasing is achieved through data independent weights which are predefined as per direction of arrival. These weights are applied to the analog phase shifter IC, which produces a set of phases in order to compensate the directional phase shifts. Signals are then combined with a power combiner. For realistic demonstration, signals from different locations are transmitted through a transmitter with a horn antenna. The beamformer successfully enhances the signal from the direction of interest.
{"title":"Hardware implementation of analog beamformer for phased array radar (PAR)","authors":"H. A. Mirza, I. Shah, F. Abbasi, M. Shafiq","doi":"10.1109/IBCAST.2012.6177588","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177588","url":null,"abstract":"Beamformer is an indispensible part of any phased array system. Analog beamformer is the simpler method where the individual signals received from array of antennas are co-phased and summed to maximize the signal reception. The co-phasing is achieved through data independent weights which are predefined as per direction of arrival. These weights are applied to the analog phase shifter IC, which produces a set of phases in order to compensate the directional phase shifts. Signals are then combined with a power combiner. For realistic demonstration, signals from different locations are transmitted through a transmitter with a horn antenna. The beamformer successfully enhances the signal from the direction of interest.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"33 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131673980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177550
A. Ahmed, A. Baig, S. Bilal, S. Zahir
The study of jet impingement on axisymmetric deflector plate is done using commercial CFD code. The problem of jet impingement was analyzed by developing a supersonic nozzle flow as free expansion and then capturing the effects of its jet impinging upon flat plate first and then deflector plate. The deflector plate was optimized for its design by varying distance between nozzle exit plane and deflector plate apex. The CFD solutions were time-variant but phenomenon of jet plume formation stabilizes after a time interval after which the effects were captured in form of pressure distribution on deflector plate.
{"title":"CFD analysis of supersonic jet impingement on axisymmetric deflector plate","authors":"A. Ahmed, A. Baig, S. Bilal, S. Zahir","doi":"10.1109/IBCAST.2012.6177550","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177550","url":null,"abstract":"The study of jet impingement on axisymmetric deflector plate is done using commercial CFD code. The problem of jet impingement was analyzed by developing a supersonic nozzle flow as free expansion and then capturing the effects of its jet impinging upon flat plate first and then deflector plate. The deflector plate was optimized for its design by varying distance between nozzle exit plane and deflector plate apex. The CFD solutions were time-variant but phenomenon of jet plume formation stabilizes after a time interval after which the effects were captured in form of pressure distribution on deflector plate.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"124933606","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177551
Imran Mahmood, Mansoor-ul-Haq, H. Rafiuddin, M. Rafique
Supersonic flow over a compression expansion corner is simulatednumerically. Three-dimensional Navier-Stokes equations have been solvedovercompression expansion corner for validation of in- house three dimensional Navier stokes code. Steger and warming flux vector splitting scheme has been used. Simulation captures all the features of complex flow problem including formation of oblique shock, expansion wave and their reflection and interaction. The results compare very well with the analytical data.
{"title":"Numerical simulation of supersonic flow over compression expansion corner using 3-D NS code","authors":"Imran Mahmood, Mansoor-ul-Haq, H. Rafiuddin, M. Rafique","doi":"10.1109/IBCAST.2012.6177551","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177551","url":null,"abstract":"Supersonic flow over a compression expansion corner is simulatednumerically. Three-dimensional Navier-Stokes equations have been solvedovercompression expansion corner for validation of in- house three dimensional Navier stokes code. Steger and warming flux vector splitting scheme has been used. Simulation captures all the features of complex flow problem including formation of oblique shock, expansion wave and their reflection and interaction. The results compare very well with the analytical data.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"116909463","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177522
Abdul Manan Khan, Amir Iqbal Bhatti, Sami-ud-Din, Q. Khan
This paper presents an application of static and dynamic sliding mode control of ball and beam system. Conventional PID controllers use incomplete simplified models and are mostly designed for linear systems. Although, some PID controllers are designed for nonlinear system but they are using simplified incomplete model which do not cater for matched disturbances. Our proposed control laws using static & dynamic sliding mode control use complete nonlinear system without model approximation. Moreover, static sliding mode control (SSMC) caters for matched disturbance rejection as well. There is an inherent issue of chattering with static sliding mode control (SSMC). However, dynamics sliding mode control (DSMC) counter it well. DSMC is not only equally effective when it comes to matched disturbance rejection but also removes chattering as well. In the end detailed comparative analysis is presented and experimental results confirm the superiority of DSMC.
{"title":"Static & dynamic sliding mode control of ball and beam system","authors":"Abdul Manan Khan, Amir Iqbal Bhatti, Sami-ud-Din, Q. Khan","doi":"10.1109/IBCAST.2012.6177522","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177522","url":null,"abstract":"This paper presents an application of static and dynamic sliding mode control of ball and beam system. Conventional PID controllers use incomplete simplified models and are mostly designed for linear systems. Although, some PID controllers are designed for nonlinear system but they are using simplified incomplete model which do not cater for matched disturbances. Our proposed control laws using static & dynamic sliding mode control use complete nonlinear system without model approximation. Moreover, static sliding mode control (SSMC) caters for matched disturbance rejection as well. There is an inherent issue of chattering with static sliding mode control (SSMC). However, dynamics sliding mode control (DSMC) counter it well. DSMC is not only equally effective when it comes to matched disturbance rejection but also removes chattering as well. In the end detailed comparative analysis is presented and experimental results confirm the superiority of DSMC.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"1 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131330384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177593
A. Mumtaz, M. K. Islam, A. Hassan, O. Khalid
We have presented a method for optical generation of doublet and triplet and presented a complete DWDM ring on single fiber with UWB generation for uplink signal. This UWB system can support 3 rings. Optical Add Drop Multiplexers are used at each UWB node to drop and insert the required wavelengths. Simulation of Self-phase modulation is done to study the effects on UWB transmission and method has been proposed to minimize the effects.
{"title":"Ultra Wide Band Radio DWDM rings with photonic UWB pulse generation and transmission in presence of non-linearities","authors":"A. Mumtaz, M. K. Islam, A. Hassan, O. Khalid","doi":"10.1109/IBCAST.2012.6177593","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177593","url":null,"abstract":"We have presented a method for optical generation of doublet and triplet and presented a complete DWDM ring on single fiber with UWB generation for uplink signal. This UWB system can support 3 rings. Optical Add Drop Multiplexers are used at each UWB node to drop and insert the required wavelengths. Simulation of Self-phase modulation is done to study the effects on UWB transmission and method has been proposed to minimize the effects.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"612 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"131735322","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177559
N. Durrani
The present study is focused to evaluate the accuracy of the Detached-Eddy Simulation (DES), Delayed Detached-Eddy Simulation (DDES) and Reynolds Averaged Navier-Stokes (RANS) equations for a mild separation case. An in-house code dynamic grid detached eddy simulation `DG-DES' is used. The modeled turbulent Reynolds stresses are computed as a reference quantity. The flow around Aerospatiale A-airfoil at maximum lift with angle of attack α=13.3° and at a Reynolds number of 2× 106 is taken as the test case. The detailed experimental data for this case is available in the open literature. The computed turbulent Reynolds stresses from DES are lower than RANS within the boundary layer at the leading edge of the suction side. It is argued to be due to the premature switching to less dissipative LES mode within boundary layer. The DDES gives comparable values to RANS, as an expected outcome. It is observed that for the cases with the mild separation, although DDES works in correct fashion in line with the basic concept of treating the whole of the boundary layer in RANS mode. However, the original DES may perform better than the DDES due to lower dissipation characteristics. The DES results on the suction side in the wake-region are encouraging and comparatively better than DDES, despite its switching problem.
{"title":"Comparison of modelled reynolds stresses for mild separation using RANS, DES and DDES schemes","authors":"N. Durrani","doi":"10.1109/IBCAST.2012.6177559","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177559","url":null,"abstract":"The present study is focused to evaluate the accuracy of the Detached-Eddy Simulation (DES), Delayed Detached-Eddy Simulation (DDES) and Reynolds Averaged Navier-Stokes (RANS) equations for a mild separation case. An in-house code dynamic grid detached eddy simulation `DG-DES' is used. The modeled turbulent Reynolds stresses are computed as a reference quantity. The flow around Aerospatiale A-airfoil at maximum lift with angle of attack α=13.3° and at a Reynolds number of 2× 106 is taken as the test case. The detailed experimental data for this case is available in the open literature. The computed turbulent Reynolds stresses from DES are lower than RANS within the boundary layer at the leading edge of the suction side. It is argued to be due to the premature switching to less dissipative LES mode within boundary layer. The DDES gives comparable values to RANS, as an expected outcome. It is observed that for the cases with the mild separation, although DDES works in correct fashion in line with the basic concept of treating the whole of the boundary layer in RANS mode. However, the original DES may perform better than the DDES due to lower dissipation characteristics. The DES results on the suction side in the wake-region are encouraging and comparatively better than DDES, despite its switching problem.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"17 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125818008","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2012-04-03DOI: 10.1109/IBCAST.2012.6177569
M. Sohail, Yan Chao, M. Husain, R. Ullah
Flow field around high speed vehicles is very complex and difficult to simulate. The boundary layers are squeezed between shock layer and body surface. Resolution of boundary layer, shock wave and turbulent regions where the flow field has high values is difficult to capture. DNS and Large eddy simulation (LES) are very good CFD techniques but these are computationally expensive. The latter allows to generate useful solutions to transient flows, while still maintaining computationally realistic problems. Detached eddy simulation (DES) is a modification of a RANS model in which the model switches to a subgrid scale formulation in regions fine enough for LES calculations. Regions near solid body boundaries and where the turbulent length scale is less than the maximum grid dimension are assigned the RANS mode of solution. As the turbulent length scale exceeds the grid dimension, these regions are solved using the LES mode. Therefore the grid resolution is not as demanding as pure LES, thereby considerably cutting down the cost of the computation. In this research study supersonic flow is simulated at Mach 4 and different angle of attacks to calculate aerodynamics characteristics. The results are compared with experimental as well as turbulence model (K-ω SST Model). The results achieved with DES simulation have very good resolution as well as have reasonable agreement with experimental and available data at low cost.
{"title":"Detached eddy simulations an economical tool for CFD","authors":"M. Sohail, Yan Chao, M. Husain, R. Ullah","doi":"10.1109/IBCAST.2012.6177569","DOIUrl":"https://doi.org/10.1109/IBCAST.2012.6177569","url":null,"abstract":"Flow field around high speed vehicles is very complex and difficult to simulate. The boundary layers are squeezed between shock layer and body surface. Resolution of boundary layer, shock wave and turbulent regions where the flow field has high values is difficult to capture. DNS and Large eddy simulation (LES) are very good CFD techniques but these are computationally expensive. The latter allows to generate useful solutions to transient flows, while still maintaining computationally realistic problems. Detached eddy simulation (DES) is a modification of a RANS model in which the model switches to a subgrid scale formulation in regions fine enough for LES calculations. Regions near solid body boundaries and where the turbulent length scale is less than the maximum grid dimension are assigned the RANS mode of solution. As the turbulent length scale exceeds the grid dimension, these regions are solved using the LES mode. Therefore the grid resolution is not as demanding as pure LES, thereby considerably cutting down the cost of the computation. In this research study supersonic flow is simulated at Mach 4 and different angle of attacks to calculate aerodynamics characteristics. The results are compared with experimental as well as turbulence model (K-ω SST Model). The results achieved with DES simulation have very good resolution as well as have reasonable agreement with experimental and available data at low cost.","PeriodicalId":251584,"journal":{"name":"Proceedings of 2012 9th International Bhurban Conference on Applied Sciences & Technology (IBCAST)","volume":"44 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2012-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"125459517","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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