| Projectile/Sabot Discard Aerodynamics. |
DEC 1979 |
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| Authors:
David Siegelman; Peter Crimi; AVCO SYSTEMS DIV WILMINGTON MA
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 | An engineering analysis procedure which describes the sabot discard process for gun-launched projectiles has been modified in order to provide an improved tool for investigating the effects of sabot, projectile and launch parameters upon near field dispersive forces. Experimental test data generated by BRL has been used to formulate an improved engineering model of the interaction flow field which develops about the projectile/sabot petal package during the removal process. The ... |
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| Theoretical Study of Leading-Edge Bubbles and Leading-Edge Stall of Airfoils. |
DEC 1977 |
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| Authors:
Peter Crimi; AVCO SYSTEMS DIV WILMINGTON MASS
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| The small separation bubbles which form near the leading edge of airfoils prior to the onset of leading-edge stall have been analyzed in detail, including the effects of viscous-inviscid interaction. The separated laminar shear layer, transitional flow and turbulent reattaching flow are represented by an integral formulation. A correlation of local shear-layer parameters has been developed for determining the onset of transition in the laminar shear layer. Solutions are obtained ... |
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| Theoretical Study of Dynamic Stall. |
APR 1974 |
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| Authors:
Peter Crimi; AVCO SYSTEMS DIV WILMINGTON MASS
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| An analysis of unsteady trailing-edge stall of a two-dimensional airfoil was carried out, the objectives being to develop tools for analysis of the general dynamic stall problem and to gain further understanding of the underlying mechanisms of the unsteady stall process. The problem was first formulated to take direct account of the interactions of the viscous and inviscid flows, but an acceptable matching of the potential-flow and viscous-flow solutions could ... |
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| Dynamic Stall, |
NOV 1973 |
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| Authors:
Peter Crimi; ADVISORY GROUP FOR AEROSPACE RESEARCH AND DEVELOPMENT PARIS (FRANCE)
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| Problems associated with unsteady stall are summarized and past experimental and theoretical studies, relating primarily to dynamic stall of helicopter rotor blades, are reviewed. The problems attendant to analytic treatment of dynamic stall, including identification of relevant flow elements and definition of unsteady separation, are then discussed, and the basis for a theory which accounts for viscous effects and viscous-inviscid interactions analytically is presented. Results of computations are compared with ... |
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| THEORETICAL PREDICTION OF THE FLOW IN THE WAKE OF A HELICOPTER ROTOR. ADDENDUM - EFFECTS DUE TO A FUSELAGE IN A CONSTANT, NONUNIFORM FLOW. |
AUG 1966 |
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| Authors:
Peter Crimi; Andrew R. Trenka; CORNELL AERONAUTICAL LAB INC BUFFALO N Y
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| The addendum reports the results of an extension to the study to determine the time varying flow in the vicinity of a helicopter rotor in hovering and forward flight and having a fuselage immersed in the rotor wake. The purpose of the extension was to compare two models representing the fuselage. The first fuselage model (AD-629 782 and AD-629 783), was based upon the assumption that the fuselage was immersed ... |
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| THEORETICAL PREDICTION OF THE FLOW IN THE WAKE OF A HELICOPTER ROTOR. PART I. DEVELOPMENT OF THEORY AND RESULTS OF COMPUTATIONS. |
SEP 1965 |
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| Authors:
Peter Crimi; CORNELL AERONAUTICAL LAB INC BUFFALO N Y
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| A study was performed with the objective of predicting the time-varying flow in the vicinity of a helicopter in hovering or forward flight. An analytical model was formulated which represents the rotor, its wake and the fuselage of the aircraft. The model for the wake has been simplified in a manner consistent with flow visualization studies by representing the wake as tip vortices emanating from each blade. The wake vortices ... |
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| THEORETICAL PREDICTION OF THE FLOW IN THE WAKE OF A HELICOPTER ROTOR. PART 2. FORMULATION AND APPLICATION OF THE ROTOR-WAKE-FLOW COMPUTER PROGRAM. |
SEP 1965 |
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| Authors:
Peter Crimi; CORNELL AERONAUTICAL LAB INC BUFFALO N Y
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| Two digital computer programs were prepared which direct the calculation of the time-varying flow in the vicinity of a helicopter rotor in forward or hovering flight. Fuselage interference effects are taken into account. The applicability of these programs to specific problems and procedures for their use are discussed. First, the assumptions made in constructing the mathematical model and the relationship of the model to the physical flow are outlined. In ... |
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| FLUTTER ANALYSIS OF A HYDROFOIL NEAR A FREE SURFACE. |
AUG 1965 |
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| Authors:
Peter Crimi; John M. Grace; CORNELL AERONAUTICAL LAB INC BUFFALO N Y
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| The flutter characteristics of a two-dimensional hydrofoil near a free surface are analyzed, with consideration given to the cases of both one and two degrees of freedom. The flutter equations incorporate lift and moment as determined from an exact linearized potential solution. Free-surface effects are included without approximation. Results indicate that for the system having two degrees of freedom, the free surface has very little effect on flutter boundaries, despite ... |
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| REPRESENTATION OF PROPELLER WAKES BY SYSTEMS OF FINITE CORE VORTICES. |
FEB 1965 |
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| Authors:
W. Gordon Brady; Peter Crimi; CORNELL AERONAUTICAL LAB INC BUFFALO N Y
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| The report discusses the development of a propeller wake model and computational procedure aimed at the determination of the spatial distribution of wake vorticity and the associated induced velocity distribution. Numerical calculations were made for a number of vortex-ring configurations corresponding to a hovering rotor at onehalf, one and two ring radii above the ground, as well as out-of-ground effect. Both unsteady and time-averaged velocities were computed at various points ... |
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Reports by Author
