Thereafter, the relationship between drag and lift with regards to wind speeds was analysed. Thirdly, the relationship between the lift forces generated on an aerofoil with varying angles of attack was analysed. Finally, the relationship between Reynolds number and wind tunnel testing was briefly described. The report is then concluded with a list of recommendations to improve further wind tunnel testing in terms of accuracy. ------------------------------------------------- Content Page ABSTRACT 2 CONTENT PAGE 3 1.0 INTRODUCTION 4 1.1 Purpose 4 1.2 Background Information 4 1.3 Methodology 4 1.4 Scope 4 2.0 EQUIPMENTS AND APPARATUS 5 2.1 Wind Tunnel 5 2.2 Asymmetrical Aerofoil 5 2.3 360° Protractor 6 3.0 PROCEDURES 7 3.1 Experiment 1 : Familiarization of wind tunnel 7 3.2 Experiment 2: Measuring Drag 8 3.3 Experiment 3: Measuring Lift 8 3.4 Experiment 4: Investigating Angle of Attack 8 4.0 RESULTS AND OBSERVATIONS 9 4.1 Drag vs. Wind Speed 9 4.2 Lift vs. Wind Speed 10 4.3 Lift vs.
Repeat steps 1-5 for the cord and elastic band 6. Determine the spring constant of each object by graphing F v. Δx for linear springs. If the graph does not appear linear, graph F v. Δx raised to the appropriate constant Part 2: 1. Predict the velocity of the spring when displaced at 0.02, 0.04, 0.06, 0.08, 0.10 meters, using the spring constant derived from part 1 2. Secure the spring to the stand 3.
Aim of experiment (1.1) The aim of this experiment is to show that the force exerted by a jet of fluid striking onto an object is equivalent to the rate of change of momentum in the jet. It is possible to observe the shape of the fluid after the impact with the flat plate. Apparatus (1.2) Impact of a jet apparatus Steady water supply with a flow control valve A flat plate Set of calibrated weights Stop watch Theory of experiment (1.3) In this experiment the rate of change is calculated directly from the change in momentum rate of the fluid before the fluid hits the plate and after the fluid hits the plate. This is a diagram of the straight plate and what will happen as the fluid impacts on the plate. Before the impact of the fluid onto the plate, the fluid is in line with the x-axis, as shows by the velocity vector labeled V1.
The pitching moment at the AC will be constant with changing AOA if velocity is constant. The AC does NOT move with changes in AOA 2.) The nature of the boundary layer determines the maximum lift coefficient and stalling characteristics of an airfoil. Define stall and state what the boundary layer is. Name and describe/define the two forces that act on the airflow in the boundary layer and how the two forces contribute to the development of stall.
Using this equation I can determine the cooling time constant for the block of steel. Observations: Below you will find the data obtained from the experiment as well as the excess temperature I calculated. Time in min Actual Temperature of Block of Steel ° C Excess Temperature in ° C 0 153 128 1 133.4 108.4 2 116.7 91.7 3 102.6 77.6 4 90.7 65.7 5 80.6 55.6 6 72.1 47.1 7 64.9 39.9 8 58.7 33.7 9 53.6 28.6 10 49.2 24.2 11 45.5 20.5 12 42.3 17.3 13 39.7 14.7 14 37.4 12.4 15 35.5 10.5 16 33.9 8.9 17 32.5 7.5 18 31.4 6.4 19 30.4 5.4 20 29.6 4.6 Chart
Assume the viscosity of air at 28,000 ft is 3.15E-7 pounds-force second/square-foot, which can also be determined using an online atmospheric calculator. Assume that the power provided by the engine is 787 Hp, which can be determined by researching the Pratt
Speed of sound in air using Resonance Purpose: In this laboratory investigation, we will determine speed of sound using the formula: speed = frequency times wavelength. Equation 1 After making several measurements of the speed of sound, we will compare our average experiment result from this lab to the speed of sound predicted by the equation vsound=330 m/s+.6m/s (T).Equation 2 Theory: Congitudinal waves are waves which the motion of the individual particles of the medium is in a direction that is parallel to the direction of energy transport. The result of a longitudinal wave is the creation of compressions and rarefactions within the air. Picture: The speed of sound in air is impacted by the temperature because sound travels by vibrating molecules and passing the energy on to a nearby molecule. Sound travels faster through warm air than cold air because the molecules in warm air vibrate faster.
We used a vernier caliper to obtain the diameter of those two and therefore, the radius. When adding all the numbers together, we found that the true radius(r) of the orbit was 0.139 m. To find our tension, we needed to find out how much weight we needed to pull the object towards away from the spring and on the tip of the pointer as shown below. The tension needed to pull the mass on the tip of the pointer 1.05 kg. In theory the force of acceleration needed to pull the mass to same exact spot should equal the force of tension multiplied by the force due to gravity. Using Newton’s second law, F=ma, we know that the
3.0 Theory The shape of an aerofoil causes the air along the top surface to speed up resulting in a negative pressure and the air on the lower section slow down resulting in a positive pressure. The combination of these two pressure regions leads to a lift force being generated. The following are the formulas used in determining the required values: Drag Force, FD=12CDρAv2 Lift Force, FL=12CLρAv2 Velocity of Flow, v=2∆Pρ Pitching Moment, M=CmqSc 4.0 Experimental Apparatus The following are the apparatus involved in the experiment: * LS 18013 educational wind tunnel * 3 Components Balance * Test Model * Test
Gravitational acceleration was found using this formula: g=2ht2 Impact speed of the falling objects was found using this formula: v=2ht Percentage error between calculated values and those obtained from the slope of the graphs were found using this formula: percent error=calculated value-slopecalculated value x100% PROCEDURE Firstly we placed the falling sphere apparatus on the table. Then we placed the meter scale next to the falling sphere