Moving-body simulations using overset framework with rigid body dynamics

Koomullil, Roy P.; Cheng, Gary; Soni, Bharat K.; Noack, Ralph W.; Prewitt, Nathan C.

doi:10.1016/j.matcom.2008.04.009

Cited by 17 publications

(5 citation statements)

References 24 publications

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“…The discretized form of the governing equations are solved in a parallel framework using MPI [12] for inter processor communication and METIS [21] to decompose the domain into multiple regions. More details on the numerical approach and validation are reported in [26][28][27][25][23][24][22][10]. …”

Section: Numerical Approachesmentioning

confidence: 99%

Assessment of surgical effects on patients with obstructive sleep apnea syndrome using computational fluid dynamics simulations

Cheng

Koomullil

Ito

et al. 2014

Mathematics and Computers in Simulation

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Obstructive sleep apnea syndrome is one of the most common sleep disorders. To treat patients with this health problem, it is important to detect the severity of this syndrome and occlusion sites in each patient. The goal of this study is to test the hypothesis that the cure of obstructive sleep apnea syndrome by maxillomandibular advancement surgery can be predicted by analyzing the effect of anatomical airway changes on the pressure effort required for normal breathing using a high-fidelity, 3-D numerical model. The employed numerical model consists of: 1) 3-D upper airway geometry construction from patient-specific computed tomographic scans using an image segmentation technique, 2) mixed-element mesh generation of the numerically constructed airway geometry for discretizing the domain of interest, and 3) computational fluid dynamics simulations for predicting the flow field within the airway and the degree of severity of breathing obstruction. In the present study, both laminar and turbulent flow simulations were performed to predict the flow field in the upper airway of the selected patients before and after maxillomandibular advancement surgery. Patients of different body mass indices were also studied to assess their effects. The numerical results were analyzed to evaluate the pressure gradient along the upper airway. The magnitude of the pressure gradient is regarded as the pressure effort required for breathing, and the extent of reduction of the pressure effort is taken to measure the success of the surgery. The description of the employed numerical model, numerical results from simulations of various patients, and suggestion for future work are detailed in this paper.

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Section: Numerical Approachesmentioning

confidence: 99%

Assessment of surgical effects on patients with obstructive sleep apnea syndrome using computational fluid dynamics simulations

Cheng

Koomullil

Ito

et al. 2014

Mathematics and Computers in Simulation

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“…A test case of wing having store is used for the calculation of the trajectory of the store. The experiments which are used for the calculation of computational results were performed in the transonic (M=0.95) flow regime with an angle of attack of zero at 26000 ft. altitude from which the static pressure and temperature values were taken see the work of Koomullil et al (2008).…”

Section: Computational Setupmentioning

confidence: 99%

Simulation of a Standard Store Separated from Generic Wing

Sheharyar

Uddin

Ali

et al. 2018

JAFM

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Evaluation of store separation experimentally is expensive; time consuming and dangerous as human risks are involved. This results in development of computational methods to simulate the store separation. Store separation studies include store separation simulation and determination of linear and angular displacements of store under the influence of complex and non-uniform flow field of parent aircraft. In order to validate the methodology, the unsteady CFD results, obtained by coupling six degrees of freedom (6-DOF) with flow solver, are compared with experimental results. Major trends are captured which are consistent with experimental results. Variation in store trajectory has been evaluated with different combinations of forward and rearward ejection forces. By increasing the magnitude of forward ejection force vertical displacement increases and store separates more safely from the wing. Moreover, effects of varying parent wing configuration on store trajectory has also been analyzed by incorporation of leading-edge flaps (LEFs). Store always separates in nose down condition due to LEFs which increases vertical displacement of store and thus safety related to store separation is enhanced.

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“…Other flow simulations based on the overset mesh approach can be found in the literature. 4,[17][18][19][20] However, the existing works focused either on singular parallel approach or on steady simulations by using overset method, and few works have addressed the hybrid parallel algorithms for unsteady problems of simulating MBS. As contemporary parallel systems consist of multicore nodes, an approach that uses a hybrid of MPI and OpenMP is very popular to make better use of multicore architectures.…”

Section: Introductionmentioning

confidence: 99%

Parallel multibody separation simulation using MPI and OpenMP with communication optimization

Liu

2018

Journal of Algorithms & Computational Technology

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In this paper we investigate parallel implementations of multibody separation simulation using a hybrid of message passing interface and OpenMP. We propose a mesh block-based overset communication optimization algorithm. After presenting details of local data structures, we present our strategy for parallelizing both the overset mesh assembler and the flow solver by employing message passing interface and OpenMP. Experimental results show that the mesh blockbased overset communication optimization algorithm has an advantage in real elapsed time when compared to a process-based implementation. The hybrid version shows that it is suitable for improving the load balance if a large number of CPU cores are used. We report results for a standard multibody separation case.

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Moving-body simulations using overset framework with rigid body dynamics

Cited by 17 publications

References 24 publications

Assessment of surgical effects on patients with obstructive sleep apnea syndrome using computational fluid dynamics simulations

Assessment of surgical effects on patients with obstructive sleep apnea syndrome using computational fluid dynamics simulations

Simulation of a Standard Store Separated from Generic Wing

Parallel multibody separation simulation using MPI and OpenMP with communication optimization

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