scholarly journals Identification of Shortcomings in the Method of Application of Probes and Improvement of the Parachute-Jet System

2020 ◽  
pp. 21-26
Author(s):  
Yu. I. Adamov
Keyword(s):  
Landing Site ◽  
Heavy Duty ◽  
Real Rate ◽  
Probability Of Error ◽  
Powder Charge ◽  
Wind Speeds ◽  
Aircraft Landing ◽  
Main Disadvantage ◽  
Optimum Height ◽  
General Improvement

The article deals with the issues of improvement of the parachute-jet system (ORS) with the use of modern radio altimeters in order to increase the percentage of soft landings and to allow adjusting the position of the landing object in the horizontal plane depending on the angle of inclination of the surface of the intersection. The experience gained in heavy-duty aircraft landing illuminates the problem of calculating the probe length required for successful lan­ding. The main disadvantage of the method of using probes is that their length is rigidly fixed long before the landing (before loading), which does not allow to adjust it to account for changes in para­meters. The main disadvantages of the technique of using OPS probes are the inability to accurately predict the temperature of the landing site, the high probability of error in determining the full mass of the object before the landing, the inability to account for the pre­sence, power of upward airflows and does not allow to adjust it to account for changes in parameters. Therefore, there is the question of improving the method of determining the optimum height for the inclusion of the powder bra­king system, which would at least improve the consideration of the above parameters to ensure a minimum landing speed of heavy machinery. This is especially true of the real rate of descent of the ORS, which mainly depends on the flight mass of the object, the tempe­rature and pressure of the atmospheric air, the temperature of the powder charge of the ORS engine, the presence and power of upward airflows that are difficult to predict accurately, and the wind speeds near the landing site, which in general Improvement of the parachute-jet system in the direction of increasing the reliability, accuracy and safety of the landing of the object by the use of radar system will allow casting safely carry heavy objects dropping from airplanes.

scholarly journals Multi-model Meteorological and Aeolian Predictions for Mars 2020 and the Jezero Crater Region

2021 ◽  
Vol 217 (1) ◽  
Author(s):  
C. E. Newman ◽  
M. de la Torre Juárez ◽  
J. Pla-García ◽  
R. J. Wilson ◽  
S. R. Lewis ◽  
...  
Keyword(s):  
Landing Site ◽  
Atmospheric Temperature ◽  
Sand Transport ◽  
Maximum Pressure ◽  
Summer Solstice ◽  
Winter Solstice ◽  
Gale Crater ◽  
Wind Speeds ◽  
Global Circulation ◽  
Aeolian Activity

AbstractNine simulations are used to predict the meteorology and aeolian activity of the Mars 2020 landing site region. Predicted seasonal variations of pressure and surface and atmospheric temperature generally agree. Minimum and maximum pressure is predicted at $\text{Ls}\sim 145^{\circ}$ Ls ∼ 145 ∘ and $250^{\circ}$ 250 ∘ , respectively. Maximum and minimum surface and atmospheric temperature are predicted at $\text{Ls}\sim 180^{\circ}$ Ls ∼ 180 ∘ and $270^{\circ}$ 270 ∘ , respectively; i.e., are warmest at northern fall equinox not summer solstice. Daily pressure cycles vary more between simulations, possibly due to differences in atmospheric dust distributions. Jezero crater sits inside and close to the NW rim of the huge Isidis basin, whose daytime upslope (∼east-southeasterly) and nighttime downslope (∼northwesterly) winds are predicted to dominate except around summer solstice, when the global circulation produces more southerly wind directions. Wind predictions vary hugely, with annual maximum speeds varying from 11 to $19~\text{ms}^{-1}$ 19 ms − 1 and daily mean wind speeds peaking in the first half of summer for most simulations but in the second half of the year for two. Most simulations predict net annual sand transport toward the WNW, which is generally consistent with aeolian observations, and peak sand fluxes in the first half of summer, with the weakest fluxes around winter solstice due to opposition between the global circulation and daytime upslope winds. However, one simulation predicts transport toward the NW, while another predicts fluxes peaking later and transport toward the WSW. Vortex activity is predicted to peak in summer and dip around winter solstice, and to be greater than at InSight and much greater than in Gale crater.

The Automobile Wagon for Heavy Duty

1900 ◽  
Vol 50 (1289supp) ◽  
pp. 20665-20668
Author(s):  
Arthur Herschmann
Keyword(s):  
Heavy Duty

Structured Data Entry for Reliable Acquisition of Pharmacokinetic Data

1996 ◽  
Vol 35 (03) ◽  
pp. 261-264 ◽  
Author(s):  
T. Schromm ◽  
T. Frankewitsch ◽  
M. Giehl ◽  
F. Keller ◽  
D. Zellner
Keyword(s):  
Text Processing ◽  
Data Entry ◽  
Processing System ◽  
Database System ◽  
Structured Data ◽  
Pharmacokinetic Parameters ◽  
Pharmacokinetic Data ◽  
Probability Of Error ◽  
Error Frequency ◽  
Estimated Error

Abstract:A pharmacokinetic database was constructed that is as free of errors as possible. Pharmacokinetic parameters were derived from the literature using a text-processing system and a database system. A random data sample from each system was compared with the original literature. The estimated error frequencies using statistical methods differed significantly between the two systems. The estimated error frequency in the text-processing system was 7.2%, that in the database system 2.7%. Compared with the original values in the literature, the estimated probability of error for identical pharmacokinetic parameters recorded in both systems is 2.4% and is not significantly different from the error frequency in the database. Parallel data entry with a text-processing system and a database system is, therefore, not significantly better than structured data entry for reducing the error frequency.

Tribotechnical Characteristics of Titanium Nitride Coating for Heavy-Duty Friction Clutches.

1980 ◽  
Vol 41 (5) ◽  
pp. 558-566
Author(s):  
O. Yu Elagina ◽  
◽  
D.O. Kolbas ◽  
A.G. Buklakov ◽  
N. Derr ◽  
...  
Keyword(s):  
Titanium Nitride ◽  
Nitride Coating ◽  
Heavy Duty ◽  
Titanium Nitride Coating ◽  
Tribotechnical Characteristics

EXPERIMENTAL AND ANALYTICAL STUDIES OF VERTICAL AXIS WIND TURBINES

2018 ◽  
pp. 51-58
Author(s):  
B. P. Khozyainov
Keyword(s):  
Wind Turbine ◽  
Flow Velocity ◽  
Wind Power ◽  
Wind Turbines ◽  
Power Efficiency ◽  
Air Flow ◽  
Geometrical Parameters ◽  
Wind Speeds ◽  
Analytical Studies ◽  
Air Flow Velocity

The article carries out the experimental and analytical studies of three-blade wind power installation and gives the technique for measurements of angular rate of wind turbine rotation depending on the wind speeds, the rotating moment and its power. We have made the comparison of the calculation results according to the formulas offered with the indicators of the wind turbine tests executed in natural conditions. The tests were carried out at wind speeds from 0.709 m/s to 6.427 m/s. The wind power efficiency (WPE) for ideal traditional installation is known to be 0.45. According to the analytical calculations, wind power efficiency of the wind turbine with 3-bladed and 6 wind guide screens at wind speedsfrom 0.709 to 6.427 is equal to 0.317, and in the range of speed from 0.709 to 4.5 m/s – 0.351, but the experimental coefficient is much higher. The analysis of WPE variations shows that the work with the wind guide screens at insignificant average air flow velocity during the set period of time appears to be more effective, than the work without them. If the air flow velocity increases, the wind power efficiency gradually decreases. Such a good fit between experimental data and analytical calculations is confirmed by comparison of F-test design criterion with its tabular values. In the design of wind turbines, it allows determining the wind turbine power, setting the geometrical parameters and mass of all details for their efficient performance.

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