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Theoretical investigation of minimum time loop maneuvers of jet aircraft


Uehara, Sachio (1974) Theoretical investigation of minimum time loop maneuvers of jet aircraft. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/ZTAZ-J396.


Minimum time loop maneuvers of high performance jet aircraft have been investigated by means of the calculus of variations. A number of simplifying assumptions have been made in the atmospheric conditions, aerodynamic parameters, and the number of controls and their upper and lower bounds, in order to obtain general features and basic characteristics of the problem. The optimal control (lift coefficient and thrust) has been determined as a function of the state variables and Lagrange multipliers. It is found that subarcs with variable thrust, or with variable lift coefficient and minimum thrust do not occur on time optimal paths. Possible transitions among the five optimal subarcs have been established by applying the corner conditions of variational calculus. These relationships are applicable to any minimum time maneuver in the vertical plane. The effects of the magnitudes of maximum lift coefficient and maximum thrust on the control program, maneuver time, final speed, and final. horizontal distance for minimum time loop maneuvers are explored through numerical computation. It is found that the control history in lift and thrust and the minimum time required for a loop maneuver depend strongly on the magnitudes of maximum lift coefficient and maximum thrust. A limited numerical exploration using more realistic aerodynamic and atmospheric parameters and a state-dependent maximum thrust yielded results in qualitative agreement with the more extensive analysis based on simplified parameters. Normal acceleration constraints are analyzed by considering the maximum lift coefficient to be a function of altitude and speed. New design criteria for the inlet, duct and engine are suggested by consideration of the problem of engine surge.

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:Aeronautics
Degree Grantor:California Institute of Technology
Division:Engineering and Applied Science
Major Option:Aeronautics
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Stewart, Homer Joseph
Thesis Committee:
  • Unknown, Unknown
Defense Date:3 May 1974
Record Number:CaltechTHESIS:09242010-111949185
Persistent URL:
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:6050
Deposited By: Dan Anguka
Deposited On:24 Sep 2010 20:44
Last Modified:21 Dec 2019 02:55

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