Wherein, the thrust fluctuation is an important factor affecting the positioning accuracy of the workpiece table. Many scholars have studied the thrust fluctuation reduction methods to improve the motor performance. Some articles optimized structure size [1], or the analytical method ignoring the end effect [2], or using look-up tables [3]. Another scholars have adopted active control strategy ...

This paper carries out the mathematical modeling, simulation, and control law design for a quadrotor with variable-pitch propellers. The use of variable-pitch propeller for thrust variation instead of RPM regulation facilitates generation of negative thrust, thereby augmenting the rate of change of thrust generation amenable for aggressive maneuvering. Blade element theory along with momentum t...

The comparisons of two typical fluidic thrust vectoring exhaust nozzles including two-dimensional(2-D) nozzle and axisymmetric nozzle on aerodynamic characteristics was presented by numerical simulation. The results show: the thrust vector angles increased with the increasing secondary flow but decreased with the nozzle pressure ratio (NPR) increasing. With the same secondary flow and NPR, the ...

Motivated by the requirement for pinpoint landing in futureMarsmissions, we consider the problemofminimumfuel powered terminal descent to a prescribed landing site. The first-order necessary conditions are derived and interpreted for a point-mass model with throttle and thrust angle control and for rigid-bodymodel with throttle and angular velocity control, clarifying the characteristics of the...

average values of< 1- t >where t is the thrust are presented for e: e: amy data and are compared with their values in hadronic interactions. as far as possible, similar analysis techniques have been employed in the two different interactions. similar variation with e is observed for this average in both data. the values of < pt> and < pl > relative to the thrust axis in e e are similar to those...

allochthonous masses are common structures in zagros fold-thrust belt. they are generally considered as collapse structures formed by the influence of gravity and in rock units with competency contrast. however, large allochthonous masses mapped in dowgonbadan area in dezful embayment near the mountain front fault (mff) of zagros show characteristics different from the belt common collapse stru...

An integrated petrologic, thermochronologic, and numerical modeling study constrains the thermal evolution of the Lesser Himalayan Sequence in the Kumaun and Garwhal regions of India. South of the Tons thrust, peak metamorphic temperatures do not exceed 330 °C. On the northern side, a transition toward higher temperatures adjacent to the Main Central thrust hanging wall is documented. In the im...

A low-power microwave arjet thruster was studied using ammonia gas as propellant. The purpose of the project was to generate ammonia plasma using a 7.5 GHz magnetron and a cylindrical cavity thruster, which is resonant in the TM001 mode [1]. The desired pressure was atmospheric or above while generating a thrust of roughly 20mN and an Isp of about 500s operating at low power (<100 kW). Introduc...

The thrust and plasma parameters generated by a Helicon Double Layer Thruster operating at a power level of 250 W with krypton propellant has been evaluated for peak magnetic field strengths of 0 to 270 G. Results show that the thrust levels achieved are dependent on the position of peak magnetic field in relation to the plasma source. Alignment of peak field strength with the plasma source exi...

A retargeting procedure is developed for use as a nonlinear low thrust guidance scheme. The selection of a control program composed of a sequence of inertially fixed thrust-acceleration vectors permits all trajectory computations to be made with closed form expressions, and allows the controls to be represented by constant parameters, thrust-acceleration vectors and thrusting times. By requirin...