Kenneth Tatum - Academia.edu (original) (raw)
Papers by Kenneth Tatum
The use o f f i n i t e elements i s explored i n a f i e l d i n which i t s use has previously ... more The use o f f i n i t e elements i s explored i n a f i e l d i n which i t s use has previously not been deemed very feasible, t h a t o f transonic flow. lem chosen i s t h a t of steady small-disturbance transonic flow. The nonlinear equations are formulated w i t h an a r t i f i c i a l v i s c o s i t y term added t o y i e l d the proper domain o f dependence and d i r e c t i o n a l bias i n supersonic regions and across imbedded shock waves. J u s t i f i c a t i o n i s given f o r the problem and means of s o l u t i o n chosen, and the p o t e n t i a l advantages o f the f i n i t e element procedure over standard f i n i t e d i fference procedures are discussed. Several possible improvements on the method as presently derived are stated.
Summary form only given. The design, development, and optimization of pulsed power machines utili... more Summary form only given. The design, development, and optimization of pulsed power machines utilizing Z-pinches of gases could be augmented by numerical simulation of gas-puffs to provide initial flow conditions of gas-puff nozzles. Gas-puff operation typically involves the expansion of a working gas such as argon from a reservoir at ∼300 K, 1 atm through a hypersonic nozzle and into
AIAA Journal, 2016
The Winslow elliptic smoothing equations have been shown to be effective for smoothing structured... more The Winslow elliptic smoothing equations have been shown to be effective for smoothing structured and unstructured computational meshes used in computational fluid dynamics applications. Although an implicit computational space is readily available for structured meshes, an explicitly constructed space is required for unstructured meshes. For a three-dimensional mesh, a method is presented where the original physical space is manipulated to generate virtual control volumes that can be employed as an effective computational space. A two-phase volume deformation scheme is implemented to effectively address mesh requirements for the viscous region near a no-slip slip surface. Region-limited smoothing is employed to fine tune the mesh smoothing to specific areas of interest and greatly increase the efficiency of the overall process. A tool called MeshGrind is used to demonstrate elliptic mesh manipulation and smoothing on practical engineering applications. Several test cases demonstrate Winslow elliptic smoo...
Computational fluid dynamics techniques were applied in support of the conceptual design of an el... more Computational fluid dynamics techniques were applied in support of the conceptual design of an electric heater for obtaining true, or near-true, flight test conditions in a continuousflow Mach 7 wind tunnel without seriously vitiating the air. The effort to date has concentrated on validation of the numerical methods for several unstructured mesh cell types and grid resolutions and for two different turbulence models, including the ability to capture unsteady transient features of simple, but similar and related, flows. Calculation results are presented for simple, isolated 2D cylinder geometries and for a bundle of 2D heat exchanger tubes representing a subset of a full heater configuration. Based upon confidence levels achieved through these validation studies, calculations of conjugate heat-transfer results for a single, hot cylinder were obtained to assist in prioritizing heater development issues.
Best Practice & Research Clinical Haematology, 2002
The Decade radiation simulator will use a Plasma Radiation Source (PRS) to provide the soft x-ray... more The Decade radiation simulator will use a Plasma Radiation Source (PRS) to provide the soft x-ray environment for DoD Nuclear Weapons Effects Testing requirements. We have made comparisons of two very different approaches to the modeling of gas flow for nozzles used in PRS z-pinches. Time-dependent, 2-D numerical simulations were performed of the gas flow through various double shell PRS
AIAA Scitech 2021 Forum, 2021
2018 Applied Aerodynamics Conference, 2018
2018 Applied Aerodynamics Conference, 2018
The use of trademarks or names of manufacturers in this report is for accurate reporting and does... more The use of trademarks or names of manufacturers in this report is for accurate reporting and does not constitute an official endorsement, either expressed or implied, of such products or manufacturers by the National Aeronautics and
Computation of Thermally Perfect Properties of Oblique Shock WavesSumnlaryA set of compressible f... more Computation of Thermally Perfect Properties of Oblique Shock WavesSumnlaryA set of compressible flow relations describ-ing flow properties across oblique shock waves,derived for a thermally perfect, caloricallyimperfect gas, is applied within the existingthermally perfect gas (TPG) computer code. Therelations are based upon a value of Cp expressedas a polynomial function of temperature. Theupdated code produces tables of compressibleflow properties of oblique shock waves, as well asthe original properties of normal shock wavesand basic isentropic flow, in a format similar tothe tables for normal shock waves found inNACA Rep. 1135. The code results are validatedin both the calorically perfect and the caloricallyimperfect, thermally perfect temperatureregimes through comparisons with the theoreti-cal methods of NACA Rep. 1135, and with astate-of-the-art computational fluid dynamicscode. The advantages of the TPG code foroblique shock wave calculations, as well as forthe properties of ...
In its Recent Advances in Multidisciplinary …, 1989
Effects of nonlinear aerodynamics and static aeroelasticity on mission performance calculations f... more Effects of nonlinear aerodynamics and static aeroelasticity on mission performance calculations for a fighter aircraft. Gary L Giles, Kenneth E Tatum, Willard E Foss In its Recent Advances in Multidisciplinary Analysis and Optimization ...
... Glenn Research Center 21000 Brookpark Road, MS 86-7 Cleveland, Ohio 44135, USA Phone: (216) 4... more ... Glenn Research Center 21000 Brookpark Road, MS 86-7 Cleveland, Ohio 44135, USA Phone: (216) 433-2188 Fax: (216) 977-7500 julianne.c.dudek ... The WIND code solves the compressible,Reynolds-averaged, Navier-Stokes equations for steady-state and unsteady flows. ...
The direct simulation Monte Carlo (DSMC) method is used to simulate the flow created prior to for... more The direct simulation Monte Carlo (DSMC) method is used to simulate the flow created prior to formation of a Z-pinch in the Nuclear Weapons Effects (NWE) Decade facility at the Arnold Engineering Development Center (AEDC). The simulation domain and the inflow boundary conditions are determined on the basis of a continuum-based Computational Fluid Dynamics (CFD) analysis. The DSMC simulation shows that the rapid expansion of the argon gas in the dual shell, concentric annular nozzle leads to large supersaturated regions. A homogeneous condensation model is then proposed for the DSMC simulation to include the effects of the nucleation and condensation, which explains the principal differences between the simulation results and available experimental data. I.
The use o f f i n i t e elements i s explored i n a f i e l d i n which i t s use has previously ... more The use o f f i n i t e elements i s explored i n a f i e l d i n which i t s use has previously not been deemed very feasible, t h a t o f transonic flow. lem chosen i s t h a t of steady small-disturbance transonic flow. The nonlinear equations are formulated w i t h an a r t i f i c i a l v i s c o s i t y term added t o y i e l d the proper domain o f dependence and d i r e c t i o n a l bias i n supersonic regions and across imbedded shock waves. J u s t i f i c a t i o n i s given f o r the problem and means of s o l u t i o n chosen, and the p o t e n t i a l advantages o f the f i n i t e element procedure over standard f i n i t e d i fference procedures are discussed. Several possible improvements on the method as presently derived are stated.
Summary form only given. The design, development, and optimization of pulsed power machines utili... more Summary form only given. The design, development, and optimization of pulsed power machines utilizing Z-pinches of gases could be augmented by numerical simulation of gas-puffs to provide initial flow conditions of gas-puff nozzles. Gas-puff operation typically involves the expansion of a working gas such as argon from a reservoir at ∼300 K, 1 atm through a hypersonic nozzle and into
AIAA Journal, 2016
The Winslow elliptic smoothing equations have been shown to be effective for smoothing structured... more The Winslow elliptic smoothing equations have been shown to be effective for smoothing structured and unstructured computational meshes used in computational fluid dynamics applications. Although an implicit computational space is readily available for structured meshes, an explicitly constructed space is required for unstructured meshes. For a three-dimensional mesh, a method is presented where the original physical space is manipulated to generate virtual control volumes that can be employed as an effective computational space. A two-phase volume deformation scheme is implemented to effectively address mesh requirements for the viscous region near a no-slip slip surface. Region-limited smoothing is employed to fine tune the mesh smoothing to specific areas of interest and greatly increase the efficiency of the overall process. A tool called MeshGrind is used to demonstrate elliptic mesh manipulation and smoothing on practical engineering applications. Several test cases demonstrate Winslow elliptic smoo...
Computational fluid dynamics techniques were applied in support of the conceptual design of an el... more Computational fluid dynamics techniques were applied in support of the conceptual design of an electric heater for obtaining true, or near-true, flight test conditions in a continuousflow Mach 7 wind tunnel without seriously vitiating the air. The effort to date has concentrated on validation of the numerical methods for several unstructured mesh cell types and grid resolutions and for two different turbulence models, including the ability to capture unsteady transient features of simple, but similar and related, flows. Calculation results are presented for simple, isolated 2D cylinder geometries and for a bundle of 2D heat exchanger tubes representing a subset of a full heater configuration. Based upon confidence levels achieved through these validation studies, calculations of conjugate heat-transfer results for a single, hot cylinder were obtained to assist in prioritizing heater development issues.
Best Practice & Research Clinical Haematology, 2002
The Decade radiation simulator will use a Plasma Radiation Source (PRS) to provide the soft x-ray... more The Decade radiation simulator will use a Plasma Radiation Source (PRS) to provide the soft x-ray environment for DoD Nuclear Weapons Effects Testing requirements. We have made comparisons of two very different approaches to the modeling of gas flow for nozzles used in PRS z-pinches. Time-dependent, 2-D numerical simulations were performed of the gas flow through various double shell PRS
AIAA Scitech 2021 Forum, 2021
2018 Applied Aerodynamics Conference, 2018
2018 Applied Aerodynamics Conference, 2018
The use of trademarks or names of manufacturers in this report is for accurate reporting and does... more The use of trademarks or names of manufacturers in this report is for accurate reporting and does not constitute an official endorsement, either expressed or implied, of such products or manufacturers by the National Aeronautics and
Computation of Thermally Perfect Properties of Oblique Shock WavesSumnlaryA set of compressible f... more Computation of Thermally Perfect Properties of Oblique Shock WavesSumnlaryA set of compressible flow relations describ-ing flow properties across oblique shock waves,derived for a thermally perfect, caloricallyimperfect gas, is applied within the existingthermally perfect gas (TPG) computer code. Therelations are based upon a value of Cp expressedas a polynomial function of temperature. Theupdated code produces tables of compressibleflow properties of oblique shock waves, as well asthe original properties of normal shock wavesand basic isentropic flow, in a format similar tothe tables for normal shock waves found inNACA Rep. 1135. The code results are validatedin both the calorically perfect and the caloricallyimperfect, thermally perfect temperatureregimes through comparisons with the theoreti-cal methods of NACA Rep. 1135, and with astate-of-the-art computational fluid dynamicscode. The advantages of the TPG code foroblique shock wave calculations, as well as forthe properties of ...
In its Recent Advances in Multidisciplinary …, 1989
Effects of nonlinear aerodynamics and static aeroelasticity on mission performance calculations f... more Effects of nonlinear aerodynamics and static aeroelasticity on mission performance calculations for a fighter aircraft. Gary L Giles, Kenneth E Tatum, Willard E Foss In its Recent Advances in Multidisciplinary Analysis and Optimization ...
... Glenn Research Center 21000 Brookpark Road, MS 86-7 Cleveland, Ohio 44135, USA Phone: (216) 4... more ... Glenn Research Center 21000 Brookpark Road, MS 86-7 Cleveland, Ohio 44135, USA Phone: (216) 433-2188 Fax: (216) 977-7500 julianne.c.dudek ... The WIND code solves the compressible,Reynolds-averaged, Navier-Stokes equations for steady-state and unsteady flows. ...
The direct simulation Monte Carlo (DSMC) method is used to simulate the flow created prior to for... more The direct simulation Monte Carlo (DSMC) method is used to simulate the flow created prior to formation of a Z-pinch in the Nuclear Weapons Effects (NWE) Decade facility at the Arnold Engineering Development Center (AEDC). The simulation domain and the inflow boundary conditions are determined on the basis of a continuum-based Computational Fluid Dynamics (CFD) analysis. The DSMC simulation shows that the rapid expansion of the argon gas in the dual shell, concentric annular nozzle leads to large supersaturated regions. A homogeneous condensation model is then proposed for the DSMC simulation to include the effects of the nucleation and condensation, which explains the principal differences between the simulation results and available experimental data. I.