BUET ENGINEERS

 1) Steady & Unsteady Flows.  2) Uniform & Non-uniform Flows.  3) Laminar & Turbulent Flows.  4) Compressible & In compressible Flows.  5) Rotational & Ir-rotational Flows.  6) One , Two & Three Dimensional Flows. Steady & Unsteady Flows:-  Steady Flows:- In which the fluid Characteristics Like velocity, pressure, density , etc. At a Point do not change with time. Unsteady Flow:- In which the fluid velocity , pressure or density at a point changes with respect to time. Uniform & Non-uniform Flow :-  Uniform Flow:- In which the velocity at given time does not change with respect to space ( length of direction of the flow ). Non-Uniform Flow:- In which the velocity at any time changes with respect to space. Changing in space Laminar & Turbulent flows:-  Laminar Flow:- in which the fluid particles move along well defined paths or stream line. Fig. Laminar Flow Turbulent Flow:- fluid moves in very irregular paths or zig – za

Lagrangian Versus Eulerian Approach Lagrangian Approach Method of description that follows the particle is referred to as the Lagrangian method of description. In Lagrangian approach we analyze a fluid flow by assuming the fluid to be composed of a very large number of particles whose motion must be described. How to do it? Identify (or label) a material of the fluid; track (or follow) it as it moves, and monitor change in its properties. The properties may be velocity, temperature, density, mass, or concentration, etc in the flow field. Eulerian Approach In control volume analyses, it is convenient to use the field, or Eulerian, method of description, which focuses attention on the properties of a flow at a given point in space as a function of time. In the Eulerian method of description, the properties of a flow field are described as functions of space coordinates and time. How to do it? Identify (or label) a certain fixed location in the flow field and follow chang

The  Lagrangian Description  is one in which individual fluid particles are tracked, much like the tracking of billiard balls in a high school physics experiment. In the Lagrangian description of fluid flow, individual fluid particles are "marked," and their positions, velocities, etc. are described as a function of time. In the example shown, particles A and B have been identified. Position vectors and velocity vectors are shown at one instant of time for each of these marked particles. As the particles move in the flow field, their potions and velocities change with time, as seen in the animated diagram. The physical laws, such as Newton's laws and conservation of mass and energy, apply directly to each particle. If there were only a few particles to consider, as in a high school physics experiment with billiard balls, the Lagrangian description would be desirable. However, fluid flow is a continuum phenomenon, at least down to the molecular level. It is not possib

1. Drafters should use a ________ in a section view of a mechanical part that includes the cylindrical view of a threaded hole. A. Center line B. Hatch line C. Poly line D. Dimension line 2. The section view drawing in which one fourth of an object has been marked for removal is known as a ________ section. A. full B. half C. quarter D. none of the above  3. In offset sections, offsets or bends in the cutting plane are all: A. 90 degrees B. 180 degrees C. Either 90 or 180 degrees D. 30, 60, or 90 degrees 4. When filling an area with a hatch pattern in AutoCAD the drafter needs to be able to ________. A. see the entire bounding area to hatch B. set Ortho on C. turn ISO grid off D. set the layer to Defpoints

1. The top, front, and bottom views align in this manner: A. Horizontally B. Vertically C. According to the planar views D. Parallel to the frontal plane 2. If a plane is parallel to the plane of projection, it appears: A. True size B. As a line or edge C. Foreshortened D. As an oblique surface 3. This line pattern is composed of three dashes, one long dash on each end with a short dash in the middle: A. Object B. Hidden C. Center D. Phantom 4. the plane upon which the top view is projected: A. Horizontal B. Frontal C. Profile D. Base 5. An advantage of this type of view is that each view shows the object all the way through as if it were transparent: A. Planar B. Horizontal C. Auxiliary D. Orthographic 6. This type of surface is tipped to all principal planes of projection and does not appear true size in any standard view: A. Foreshortened B. Parallel C. Orthographic D. Oblique

1. The primary unit of measurement for engineering drawings and design in the mechanical industries is the: A. Millimeter B. Centimeter C. Meter D. Kilometer 2. These units are based on inch-foot and yard measurements: A. International customary units B. U.S. metric units C. U.S. customary units D. ISO international units 3. This is how axonometric, oblique, and perspective sketches show objects: A. Orthographically B. Pictorially C. Obliquely D. Parallel Axonometric projection  is a type of  orthographic projection  used for creating a pictorial drawing of an object, where the lines of sight are perpendicular to the plane of projection, and the object is rotated around one or more of its axes to reveal multiple sides. 4. This type of projection is when projectors are parallel to each other, but are at an angle other than 90 degrees to the plane of projection: A. Oblique projection B. Perpendicular projection C. Aesthetic proj

Architect's scale Edit A triangular architect's scale, made of  brass An architect's scale is a specialized  ruler  designed to facilitate the drafting and measuring of  architectural drawings , such as  floor plans  and  orthographic projections . In scientific and engineering terminology, a device to measure linear distance and create proportional linear measurements is called a scale. A device for drawing straight lines is a straight edge or  ruler . In common usage both are referred to as a ruler. Because the  scale  of such drawings are often smaller than life-size, an architect's scale features multiple  units of length  and proportional length increments. For accuracy and longevity, the material used should be dimensionally stable and durable. Scales were traditionally made of wood, but today they are usually made of rigid  plastic  or  aluminium . Architect's scales may be flat, with 4 scales, or have a symmetric 3-lobed cross-section, with 6 s