scholarly journals Local Temperature Sensitivity Coefficients of a Deterred Spherical Single Base Gun Propellant

2017 ◽  
Vol 14 (4) ◽  
pp. 952-965 ◽  
Author(s):  
Moulai Karim BOULKADID ◽  
Michel. H. LEFEBVRE ◽  
Laurence JEUNIEAU ◽  
Alain DEJEAIFVE
Keyword(s):  
Temperature Sensitivity ◽  
Local Temperature ◽  
Single Base ◽  
Sensitivity Coefficients

Temperature Sensitivity Coefficients of RDX‐Based Propellants and Their Mixed Charges

2021 ◽  
Author(s):  
You Fu ◽  
Yao Zhu ◽  
Zhitao Liu ◽  
Bin Xu ◽  
Jinpeng Shen ◽  
...  
Keyword(s):  
Temperature Sensitivity ◽  
Sensitivity Coefficients

Temperature-Driven Rise in Extreme Sub-Hourly Rainfall

2019 ◽  
Vol 32 (22) ◽  
pp. 7597-7609 ◽  
Author(s):  
G. Bürger ◽  
A. Pfister ◽  
A. Bronstert
Keyword(s):  
Temporal Resolution ◽  
Temperature Sensitivity ◽  
Global Climate ◽  
Cascade Model ◽  
Local Temperature ◽  
Return Levels ◽  
Hourly Rainfall

Abstract Estimates of present and future extreme sub-hourly rainfall are derived from a daily spatial followed by a sub-daily temporal downscaling, the latter of which incorporates a novel, and crucial, temperature sensitivity. Specifically, daily global climate fields are spatially downscaled to local temperature T and precipitation P, which are then disaggregated to a temporal resolution of 10 min using a multiplicative random cascade model. The scheme is calibrated and validated with a group of 21 station records of 10-min resolution in Germany. The cascade model is used in the classical (denoted as MC) and in the new T-sensitive (MC+) version, which respects local Clausius–Clapeyron (CC) effects such as CC scaling. Extreme P is positively biased in both MC versions. Observed T sensitivity is absent in MC but well reproduced by MC+. Long-term positive trends in extreme sub-hourly P are generally more pronounced and more significant in MC+ than in MC. In units of 10-min rainfall, observed centennial trends in annual exceedance counts (EC) of P > 5 mm are +29% and in 3-yr return levels (RL) +27%. For the RCP4.5-simulated future, higher extremes are projected in both versions MC and MC+: per century, EC increases by 30% for MC and by 83% for MC+; the RL rises by 14% for MC and by 33% for MC+. Because the projected daily P trends are negligible, the sub-daily signal is mainly driven by local temperature.

Study on the Performance of the Modified Single Base Gun Propellant

2011 ◽  
Vol 415-417 ◽  
pp. 1656-1661 ◽  
Author(s):  
Bo Liu ◽  
Qiong Lin Wang ◽  
Shao Wu Liu ◽  
Hui Fang Yu ◽  
Da Li ◽  
...  
Keyword(s):  
Low Temperature ◽  
Temperature Sensitivity ◽  
Water Medium ◽  
Ballistic Performance ◽  
Near Surface ◽  
Single Base ◽  
Muzzle Velocity ◽  
Bomb Test ◽  
Ballistic Test ◽  
Propellant Charge

The modified single base gun propellant was prepared from single base propellant grain by impregnation with blasting oil, followed by deterring with deterrent in water medium. The concentration profile of function component in the propellant was studied by Fourier Transform Infrared (FTIR) Microspectroscopy. The combustion performance of the propellant was investigated by means of closed-bomb test and interior ballistic test. The barrel erosion was characterized by erosion tube test. It is found that the curve of nitroglycerine concentration is just like a parabola along the radius and the polymer ester concentration in the near surface of propellant decreases exponentially from the surface inwards. Compared with the single base gun propellant, the modified single base gun propellant burns more progressively and the value of Pr increases from 0.097 to 0.424. The interior ballistic performance for this propellant charge is improved obviously. The muzzle velocity increases by 5.0% from 886.6 m/s to 931.3 m/s. The modified single base gun propellant has the characteristic of low temperature sensitivity and the barrel erosion of this propellant decreases by 26.6% at least. The modified single base gun propellant has the advantages of higher muzzle velocity, higher combustion progressivity, low erosion and low temperature sensitivity.

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