Paul Farrell – författare

Current standard numerical methods are of little use in solving mathematical problems involving boundary layers. In Robust Computational Techniques for Boundary Layers, the authors construct numerical methods for solving problems involving differential equations that have non-smooth solutions with singularities related to boundary layers. They present a new numerical technique that provides precise results in the boundary layer regions for the problems discussed in the book. They show that this technique can be adapted in a natural way to a real flow problem, and that it can be used to construct benchmark solutions for comparison with solutions found using other numerical techniques.Focusing on robustness, simplicity, and wide applicability rather than on optimality, Robust Computational Techniques for Boundary Layers provides readers with an understanding of the underlying principles and the essential components needed for the construction of numerical methods for boundary layer problems. It explains the fundamental ideas through physical insight, model problems, and computational experiments and gives details of the linear solvers used in the computations so that readers can implement the methods and reproduce the numerical results.

From river to harbor to ocean, tugboats are among the most ubiquitous but underappreciated craft afloat. Whether maneuvering ships out from between tight harbor finger piers, pushing rafts of forty barges up the Mississippi, towing enormous oil rigs, or just delivering huge piles of gravel to a river port near you, tugs exude a sense of genial strength guided by the wise experience of their crews. We can admire the precision of their coordination, the determination in their movements, the glow of signal lights at night, silently communicating their condition and intentions to vessels nearby. It is nearly impossible not to be intrigued and impressed by the way tugs work.In Tugboats Illustrated, Paul Farrell traces the evolution, design, and role of tugboats, ranging from the first steam-powered tug to today’s hyper-specialized offshore workboats. Through extensive photographs, dynamic drawings, and enlightening diagrams, he explores the development of these hard-working boats, always shaped by the demands of their waterborne environment, by an ever-present element of danger, and by advancements in technology. Whether making impossible turns in small spaces, crashing through huge swells, pushing or pulling or prodding or coaxing or escorting, we come to understand not only what tugs do, but how physics and engineering allow them to do it.From the deck layout of a nineteenth-century sidewheel tug to the mechanics of barge towing—whether by humans, mules, steam or diesel engines—to the advantages of various types and configurations of propulsion systems, to the operation of an oil rig anchor-handling tug/supply vessel, Tugboats Illustrated is a comprehensive tribute to these beloved workhorses of the sea and their intrepid crews.

Current standard numerical methods are of little use in solving mathematical problems involving boundary layers. In Robust Computational Techniques for Boundary Layers, the authors construct numerical methods for solving problems involving differential equations that have non-smooth solutions with singularities related to boundary layers. They present a new numerical technique that provides precise results in the boundary layer regions for the problems discussed in the book. They show that this technique can be adapted in a natural way to a real flow problem, and that it can be used to construct benchmark solutions for comparison with solutions found using other numerical techniques.Focusing on robustness, simplicity, and wide applicability rather than on optimality, Robust Computational Techniques for Boundary Layers provides readers with an understanding of the underlying principles and the essential components needed for the construction of numerical methods for boundary layer problems. It explains the fundamental ideas through physical insight, model problems, and computational experiments and gives details of the linear solvers used in the computations so that readers can implement the methods and reproduce the numerical results.

Paul Farrell's stackable cards are creative fun for all the family Turrets, ramparts, windows, walls, roofs and more – create your own medieval masterpiece.Each box contains 64 cards (105 x 69 mm) in a variety of graphic designs. Clever paper engineering allows you to slot the cards together, building up and out in whichever way you like! Also included is a short booklet, with information on the architecture of castles and suggestions of card building methods. The instructions tell you how to build a castle, or you can let your imagination run riot and design your own!Renowned illustrator Paul Farrell has designed these cards in a cool, graphic style – turning the image of a castle into a work of art.

Paul Farrell's stackable cards are fun for all the family Build a skyscraper using the beautifully-designed cards, with only your imagination to limit you.Each pack contains 64 cards (105 x 69 mm) in a variety of graphic designs. Clever paper engineering allows you to slot the cards together, building up and out in whichever way you like! Also included is a short booklet, with descriptions of the key elements of a skyscraper and suggestions of how to build your masterpiece. You can go traditional or get abstract and construct your own crazy high-rise!Renowned illustrator Paul Farrell has designed these cards in a cool, graphic style – turning the image of a skyscraper into a work of art.Fun, educational, creative and mindful. The sky's the limit!

Finnlay, Rudi and Harrison are three ordinary boys, living in a farmhouse with their parents and grandparents. When they encounter a soul imprisoned in stone by the witch who lives in the woods, their lives abruptly become far more interesting, and far more dangerous. If they can defeat the witch and her protectors, the stone will become human again. But the threat may be greater than they know, and only their bond as brothers can save them.