Engineering topics

Norment, H. G.

Publications and source records attributed to Norment, H. G..

4 records

NASA NTRS1987

Three-dimensional trajectory analyses of two drop sizing instruments - PMS OAP and PMS FSSP

Flow-induced distortions of water drop fluxes and speeds as seen by the PMS optical array probe (OAP) and the PMS forward scattering spectrometer probe (FSSP) are estimated via three-dimensional flow and trajectory calculation methods. The sensitivities of the instruments to water drop diameter, angle of attack, and free stream air speed are determined. The instruments are first placed in isolation and then mounted under the wing of a Twin Otter airplane. For the wing-mounted OAP at 4-deg angle of attack, partial flow stagnation under the uptilted wing causes a significant decrease in both the flux and speed for small water drops. For the wing-mounted FSSP, sensitivity is found to both angle of attack and free stream air speed.

Norment, H. G.↗

NASA NTRS1985

Calculation of water drop trajectories to and about arbitrary three-dimensional lifting and nonlifting bodies in potential airflow

Subsonic, external flow about nonlifting bodies, lifting bodies or combinations of lifting and nonlifting bodies is calculated by a modified version of the Hess lifting code. Trajectory calculations can be performed for any atmospheric conditions and for all water drop sizes, from the smallest cloud droplet to large raindrops. Experimental water drop drag relations are used in the water drop equations of motion and effects of gravity settling are included. Inlet flow can be accommodated, and high Mach number compressibility effects are corrected for approximately. Seven codes are described: (1) a code used to debug and plot body surface description data; (2) a code that processes the body surface data to yield the potential flow field; (3) a code that computes flow velocities at arrays of points in space; (4) a code that computes water drop trajectories from an array of points in space; (5) a code that computes water drop trajectories and fluxes to arbitrary target points; (6) a code that computes water drop trajectories tangent to the body; and (7) a code that produces stereo pair plots which include both the body and trajectories. Accuracy of the calculations is discussed, and trajectory calculation results are compared with prior calculations and with experimental data.

Norment, H. G.↗

NASA NTRS1985

Three-dimensional airflow and hydrometeor trajectory calculation with applications

Numerical codes developed to model potential flows about three-dimensional bodies and applied to examining the flowfields around aircraft nose probes for gathering hydrometeor data are described. The potential flow code accounts for lifting or nonlifting surfaces, the effects of lift vorticity, inlet flows, and compression effects. Particle trajectories are calculated using particle equations of motion, with note taken of conditions in both the far- and near-fields of the flow. Graphic projections of the trajectories can be made from any view angle using another code. The codes also contain routines for handling flow velocities around arrays of spatial locations, trajectory arrays, and the effects of flow distortion on the particle flux.

Norment, H. G.↗

NASA NTRS1980

Calculation of Water Drop Trajectories to and About Arbitrary Three-Dimensional Bodies in Potential Airflow

Calculations can be performed for any atmospheric conditions and for all water drop sizes, from the smallest cloud droplet to large raindrops. Any subsonic, external, non-lifting flow can be accommodated; flow into, but not through, inlets also can be simulated. Experimental water drop drag relations are used in the water drop equations of motion and effects of gravity settling are included. Seven codes are described: (1) a code used to debug and plot body surface description data; (2) a code that processes the body surface data to yield the potential flow field; (3) a code that computes flow velocities at arrays of points in space; (4) a code that computes water drop trajectories from an array of points in space; (5) a code that computes water drop trajectories and fluxes to arbitrary target points; (6) a code that computes water drop trajectories tangent to the body; and (7) a code that produces stereo pair plots which include both the body and trajectories. Code descriptions include operating instructions, card inputs and printouts for example problems, and listing of the FORTRAN codes. Accuracy of the calculations is discussed, and trajectory calculation results are compared with prior calculations and with experimental data.

Norment, H. G.↗