Downloads & Free Reading Options - Results

This thesis describes the analysis of the reentry dynamics of a high-performance lifting atmospheric entry vehicle through numerical simulation tools. The vehicle, named SHARP, is currently being developed by the Thermal Protection Materials and Systems branch of NASA Ames Research Center, Moffett Field, California. The goal of this project is to provide insight into trajectory tradeoffs and vehicle dynamics using simulation tools that are powerful, flexible, user-friendly and inexpensive. Implemented Using MATLAB and SIMULINK, these tools are developed with an eye towards further use in the conceptual design of the SHARP vehicle's trajectory and flight control systems. A trajectory simulator is used to quantify the entry capabilities of the vehicle subject to various operational constraints. Using an aerodynamic database computed by NASA and a model of the earth, the simulator generates the vehicle trajectory in three-dimensional space based on aerodynamic angle inputs. Requirements for entry along the SHARP aerothermal performance constraint are evaluated for different control strategies. Effect of vehicle mass on entry parameters is investigated, and the cross range capability of the vehicle is evaluated. Trajectory results are presented and interpreted. A six degree of freedom simulator builds on the trajectory simulator and provides attitude simulation for future entry controls development. A Newtonian aerodynamic model including control surfaces and a mass model are developed. A visualization tool for interpreting simulation results is described. Control surfaces are roughly sized. A simple controller is developed to fly the vehicle along its aerothermal performance constraint using aerodynamic flaps for control. This end-to-end demonstration proves the suitability of the 6-DOF simulator for future flight control system development. Finally, issues surrounding real-time simulation with hardware in the loop are discussed.

TF 1618 "Atmospheric Penetration: Basic Dynamics of Re-entry"

TF 1618 "Atmospheric Penetration: Basic Dynamics of Re-entry"

This thesis describes the analysis of the reentry dynamics of a high-performance lifting atmospheric entry vehicle through numerical simulation tools. The vehicle, named SHARP, is currently being developed by the Thermal Protection Materials and Systems branch of NASA Ames Research Center, Moffett Field, California. The goal of this project is to provide insight into trajectory tradeoffs and vehicle dynamics using simulation tools that are powerful, flexible, user-friendly and inexpensive. Implemented Using MATLAB and SIMULINK, these tools are developed with an eye towards further use in the conceptual design of the SHARP vehicle's trajectory and flight control systems. A trajectory simulator is used to quantify the entry capabilities of the vehicle subject to various operational constraints. Using an aerodynamic database computed by NASA and a model of the earth, the simulator generates the vehicle trajectory in three-dimensional space based on aerodynamic angle inputs. Requirements for entry along the SHARP aerothermal performance constraint are evaluated for different control strategies. Effect of vehicle mass on entry parameters is investigated, and the cross range capability of the vehicle is evaluated. Trajectory results are presented and interpreted. A six degree of freedom simulator builds on the trajectory simulator and provides attitude simulation for future entry controls development. A Newtonian aerodynamic model including control surfaces and a mass model are developed. A visualization tool for interpreting simulation results is described. Control surfaces are roughly sized. A simple controller is developed to fly the vehicle along its aerothermal performance constraint using aerodynamic flaps for control. This end-to-end demonstration proves the suitability of the 6-DOF simulator for future flight control system development. Finally, issues surrounding real-time simulation with hardware in the loop are discussed.

1Christmas Eve At Swamp's End

By Norman Duncan

Four selected chapters from The Measure Of A Man; A Tale of the Big Woods, by Norman Duncan. What could be more Christmasy than: Babies, especially a homeless one; a woman who loves; a man who protects; a cold night; glittering stars; poor working-men witnesses; gifts. ( Title page and david wales)

A tale of a singular man at work among lumber-jacks. Duncan's droll style and tongue-in-cheek viewpoint keep the reader and listener much entertained. - Summary by Book preface and david wales

3Imperialist

By Sara Jeannette Duncan

“The Imperialist,” a novel by Sara Jeannette Duncan, published in 1904, is a portrait of life in small-town Ontario at the beginning of the 20th century. <br> At that time, English Canada was torn between affectionate loyalty for the “mother country” (Britain), and, on the other side, hard-headed respect for the demands of life in the shadow of the dynamic American economy. (In a by-election, one party pushes for establishing a preferred trading relationship between Canada and Britain: this is the “imperialist” position referred to by the book’s title.)<br> Main characters find themselves in problematic love stories that unfold against the backdrop of a society that is working out its national identity. These national issues would continue to vex Canada for decades to come. The author is ambivalent about the larger debates, but offers richly specific, subtle, and entertaining observations of manners and morals.<br> In the decades since publication, “The Imperialist” has been increasingly appreciated as a landmark in Canadian fiction. Critic and scholar Peter Allen has written: “Duncan is an eloquent and important witness to the ambiguity of [Canada’s] developing national identity in the years before World War I.”<br><br> NOTE: In this novel, a brief depiction of Native Canadians uses what we today recognize as offensive stereotypes. It is LibriVox policy to record texts as their authors originally intended. *<br> - Summary by Bruce Pirie

4Daughter of Today

By Sara Jeannette Duncan

The Canadian author Sara Jeannette Duncan (aka Mrs. Everard Cotes) is today best known for her 1904 novel of Ontario life, “The Imperialist” (also available as a LibriVox recording), but in Duncan’s own time readers were impressed more by her other works, including “A Daughter of Today,” published in 1894. “A Daughter of Today” follows the story of Elfrida Bell, a young woman who escapes the American Midwest to pursue first an artistic education in Paris, and then a novice career in journalism in London. As the novel’s title indicates, Elfrida is a product “of today,” i.e., of her day — the 1890s. She is swept up in the heady notions of that period: Aestheticism (“art for art’s sake”), fin-de-siècle Decadence, and ideas about the “New Woman” who breaks free of bourgeois conventions. With the self-absorption of youth, Elfrida sets about constructing herself along these lines. She pursues this project with bracing energy, mixed with pretension and affectation: “In nothing that she said or did, admired or condemned, was there any trace of the commonplace, except, perhaps, the desire to avoid it.” Early reviewers debated whether the character of Elfrida was “fresh and original,” or simply “ill-bred.” This novel explores clashes between convention and originality, cultural differences (American /French /British), and rivalry between friends. - Summary by Bruce Pirie

5Adventures of Billy Topsail

By Norman Duncan

The first book in a trilogy about Billy Topsail and his dog skipper as they experience a series of adventures that will challenge Billy's courage and resourcefulness, as he navigates the dangers of the sea and the rugged environment surrounding his home in Ruddy Cove, Newfoundland. - Summary by Jessie Percival

6Billy Topsail and Company: A Story for Boys

By Norman Duncan

Every boy who knows Billy Topsail will welcome this continuation of his adventuresome life in the North. Like its predecessor, the new volume is a stirring story for boys, true to life, among the hardy sons of the sea, clean, pure and stimulating. - Summary by Book Cover

7Billy Topsail, M.D.: A Tale of Adventure With Doctor Luke of Labrador

By Norman Duncan

The further adventures of Billy Topsail and Archie Armstrong on the ice, in the forest and at sea. In a singular manner the boys fall in with a doctor of the outposts and are moved to join forces with him. The doctor is Doctor Luke of the Labrador whose prototype as every one knows is Doctor Grenfell. Its pages are as crowded with brisk adventures as those of the preceding books. - Summary by Book Cover