Pressure Volume Diagrams - Coursework Example

PV DIAGRAMS Name Institution Instructor Date Contents Introduction 2 Objectives of the experiment 3 Experimental procedure 4 Experimental theory 5 6 The diagram above is a representation of a description crankshaft geometry. It illustrates the layout of piston pin as well as other features (Srinivasan, 2004). 6 Where; 6 r = crank radius at half of the stroke 6 A = crank angle from the top dead centre 6 l = length of the rod 6 X = position of the piston in relation to the crank centre 6 P = pin of the piston 6 O = crank centre 6 N = pin of the crank 7 a = Pin piston acceleration in the upward direction along the centreline 7 V= piston velocity in the upward direction along the centreline of the cylinder 7 ω= angular velocity of the crank in radian s per second 7 Considering the diagram indicated above, a triangle is formed which is denoted by NOP. Considering the use of cosine rule in analysing the values and parameters on the triangle under consideration, the equations and formulas are derived and illustrated as indicated below (Demirel, 2012): 7 8 Results and Discussion 8 Conclusion 11 References 12 Introduction Pressure volume diagrams are useful indicators in the study of various thermodynamic cycles. Discharge and suction pressures can be subjected to alignment in relation values from their reactions and behaviours. Values of average pressure are considered as the discharge and suction line pressures that are shown through the pressure measuring gauges. The explanation of all this information can be simplifies through illustration on a pressure volume diagram A pressure verses volume (PV) diagram is an important indicator of the pressure distribution in relation to the that is used up or consumed in certain engine cycle operation. Pressure volume diagrams are typical representations and illustrations of thermodynamic reactions involving energy utilisation and production. The reaction in the engine operates until it comes to an end but this does not necessary change the state of the system since there are certain parameters that are kept at constant such as the pressure ration and compression ratio. This is an implication that the cycle of the engine system returns to the initial pressure and volume. The pressure volume diagrams are sometimes used in indicating and illustration the state of reaction at any one particular point. The introduction and development of the pressure volume diagrams is was aimed at the enhancement of the efficiencies that are related to the functionality and energy utilisation for the engines under consideration. A wide application and usage in industries employs the use pressure-volume diagrams in engineering and industrial thermodynamics (Demirel, 2012). The amount or extent of work done in cycle represented by a pressure volume diagram is indicated through the computation of the area unclosed by the curve. The application of the pressure volume curved are derived through the representation of indicator curves, which play an important role when it comes to estimating the efficiencies of the engines involved in such cycles. The PV diagram is important in the performance of measurement and recording the amounts of pressure and volumes trough the operation of an engine or a thermodynamic system (Rathakrishnan, 2005). Objectives of the experiment The performance of this experiment was aimed at meeting several objectives. These objectives include: 1. To clearly understand the operating principles and features of a thermodynamic system 2. To compare and contrast between the functionality and features of a four stroke diesel and gasoline (petrol) engine cycles 3. To represent and interpret information regarding different thermodynamic cycles on the pressure volume diagrams 4. To determine the parameters that affect the efficiencies and functionality of both diesel and petrol (gasoline) engine cycles Experimental procedure The engine was subjected to turning according to the certain procedural stages as follows: The initial stage comprised the reproducing the spread sheet, which bore the indication of a single cycle for a diesel engine having four strokes. The results obtained here were then used was to come up with several enhancements with the layout and labelling so as to obtain clear set of outcomes. At this initial stage, several useful formulas were derived to assist in the computation of the required parameters later in the experiment. The experiment then proceeded to the second stage where there was the tuning of the diesel engine. This was achieved by altering the profile displayed by the heat produced. The dissipated power was then raised to a maximum possible value that was measured to be 0.9 units. The profile of the reaction was then shown in the curve at the top. The pressure was also raised to a value that made sure the pressure of combustion chamber was maintained at most 20 bar. The aim of this was the prevention of incidences of blow-ups in the engine. The third stage of the procedure for this particular experiment involved modifying the engine. This was done by converting the diesel engine to a gasoline engine. This meant that the compression ration was reduced whereas the maximum pressure limit was maintained at 20 bar. In this case, there were similarities with regard to the amount of fuel used on the diesel engine. After this, the petro engine was turned by way of altering the heat release profile. The result of this was a change in the nature of the pressure volume diagram, which stimulated a spark explosion. The production of power was then investigated in relation to its amount. The fourth stage in this experimental procedure involved explaining the outcome of the experimental performance in tabulated and graphical formats Experimental theory PV diagrams are usually used as indicators of the common features that are that make up the operation of a four-stroke engine cycle as a thermodynamic system. The pressure volume diagram offers a clear and elaborate illustration of all the states that exist in these entire cycles. The pressure volume diagram also identifies and describes the reaction paths existing between the various states in the cycles (Demirel, 2012). An important and elaborate way of describing the pressure volume diagram for a thermodynamic system involving the flow and transfer of different amounts of energies relies on accurate plotting of the curve with regard to the available information. The use of charts and diagrams in the analysis and evaluation of the different engine performances offers a practical interaction with the features and the nature of the thermodynamic systems under consideration. This can be demonstrated trough the practical computation of significant parameters while maintaining others at constant. In a typical pressure volume diagram, different processes are numerically represented in a manner that makes it possible to trace the flow of energy through the system to the point where there is work done or energy dissipated (Rathakrishnan, 2005). The diagram above is a representation of a description crankshaft geometry. It illustrates the layout of piston pin as well as other features (Srinivasan, 2004). Where; r = crank radius at half of the stroke A = crank angle from the top dead centre l = length of the rod X = position of the piston in relation to the crank centre P = pin of the piston O = crank centre N = pin of the crank a = Pin piston acceleration in the upward direction along the centreline V= piston velocity in the upward direction along the centreline of the cylinder ω= angular velocity of the crank in radian s per second Considering the diagram indicated above, a triangle is formed which is denoted by NOP. Considering the use of cosine rule in analysing the values and parameters on the triangle under consideration, the equations and formulas are derived and illustrated as indicated below (Demirel, 2012): Results and Discussion The experimental information and values were obtained and recorded in a tabulated format for various cases and sown below: The table below indicates the results obtained as a result of the experiment involving the diesel engine cycle. Angle 355 360 365 370 375 380 385 390 395 400 Total Heat Release 0.003 0.05 0.02 0.12 0.06 0.02 0.08 0.02 0.031 0.061 0.465 The compression ratio was set as at a value that did not exceed 0.9 and the area of the pv diagram was maximized as much as possible. Graph of heat release against the crank angle for the diesel engine cycle The following set of values were was used in the determination of the operation of the curve displayed the petrol engine cycle. This was achieved as a result of the modification the of the cycle for the diesel engine and the ration of compression was maintained at 20 to 1 Table showing the outcomes of the experimental performance for heat released and crank angle for the case of a petrol engine cycle. Angle 355 360 365 370 375 380 385 390 395 400 Total Heat Release 0.018 0.007 0.003 0.012 0.024 0.013 0.001 0.003 0.0008 0.0065 0.0883 Graph of heat release against the crank angle for the petrol engine cycle   355 360 365 370 375 380 385 390 395 400 Total Heat Release 0.018 0.007 0.003 0.012 0.024 0.013 0.001 0.003 0.0008 0.0065 0.0883 Angle 355 360 365 370 375 380 385 390 395 400 Total Heat Release 0.003 0.05 0.02 0.12 0.06 0.02 0.08 0.02 0.031 0.061 0.465 The table above indicates a comparison of the results obtained from of the experiment involving the diesel engine cycle and petrol engine cycles. In the case of this experiment, the operation efficiency of the systems obtained could be identified through the ration of the energy output to that of the energy used up by the system in with regard to fuel supply. The determination of the thermal efficiency is normally based on the power of the brake as well as the indicated power. The results in this particular experiment clearly indicate the efficiencies of the cycles through which the fuel energy is consumed for the purpose of production of the mechanical action. This process involves the conversion of the available fuel into mechanical power. The overall efficiency of the system is a representation of the effectiveness with which the different processes in the engine system are taking place. The engine systems considered in this particular experiment were utilising temperatures between various states to perform work. The difference in temperatures between different states is attributable to the amount of fuel taken in at any one particular intake stroke. The engine efficiency is a representation of the work performed divided by the amount of energy that is available for use in the system (Demirel, 2012). Conclusion In conclusion, carrying out of this experimentation study and the discussion of the outcomes was very significant role in describing the functional conditions and major characteristics of both diesel and gasoline engines. This is clearly demonstrated through an investigation into the nature of the pressure volume curves that are drawn to represent by the cycle systems under consideration. The experiment was very useful in establishing the relationship between the variability of the key parameters and the manner in which this variation affected the outcome with regard to the engine performance References Demirel, Y. (2012). Energy production, conversion, storage, conservation, and coupling. London, Springer. Rathakrishnan, E. (2005). Fundamentals of engineering thermodynamics. New Delhi, Prentice Hall. Read More

Objectives of the experiment The performance of this experiment was aimed at meeting several objectives. These objectives include: 1. To clearly understand the operating principles and features of a thermodynamic system 2. To compare and contrast between the functionality and features of a four stroke diesel and gasoline (petrol) engine cycles 3. To represent and interpret information regarding different thermodynamic cycles on the pressure volume diagrams 4. To determine the parameters that affect the efficiencies and functionality of both diesel and petrol (gasoline) engine cycles Experimental procedure The engine was subjected to turning according to the certain procedural stages as follows: The initial stage comprised the reproducing the spread sheet, which bore the indication of a single cycle for a diesel engine having four strokes.

The results obtained here were then used was to come up with several enhancements with the layout and labelling so as to obtain clear set of outcomes. At this initial stage, several useful formulas were derived to assist in the computation of the required parameters later in the experiment. The experiment then proceeded to the second stage where there was the tuning of the diesel engine. This was achieved by altering the profile displayed by the heat produced. The dissipated power was then raised to a maximum possible value that was measured to be 0.9 units. The profile of the reaction was then shown in the curve at the top.

The pressure was also raised to a value that made sure the pressure of combustion chamber was maintained at most 20 bar. The aim of this was the prevention of incidences of blow-ups in the engine. The third stage of the procedure for this particular experiment involved modifying the engine. This was done by converting the diesel engine to a gasoline engine. This meant that the compression ration was reduced whereas the maximum pressure limit was maintained at 20 bar. In this case, there were similarities with regard to the amount of fuel used on the diesel engine.

After this, the petro engine was turned by way of altering the heat release profile. The result of this was a change in the nature of the pressure volume diagram, which stimulated a spark explosion. The production of power was then investigated in relation to its amount. The fourth stage in this experimental procedure involved explaining the outcome of the experimental performance in tabulated and graphical formats Experimental theory PV diagrams are usually used as indicators of the common features that are that make up the operation of a four-stroke engine cycle as a thermodynamic system.

The pressure volume diagram offers a clear and elaborate illustration of all the states that exist in these entire cycles. The pressure volume diagram also identifies and describes the reaction paths existing between the various states in the cycles (Demirel, 2012). An important and elaborate way of describing the pressure volume diagram for a thermodynamic system involving the flow and transfer of different amounts of energies relies on accurate plotting of the curve with regard to the available information.

The use of charts and diagrams in the analysis and evaluation of the different engine performances offers a practical interaction with the features and the nature of the thermodynamic systems under consideration. This can be demonstrated trough the practical computation of significant parameters while maintaining others at constant. In a typical pressure volume diagram, different processes are numerically represented in a manner that makes it possible to trace the flow of energy through the system to the point where there is work done or energy dissipated (Rathakrishnan, 2005).

The diagram above is a representation of a description crankshaft geometry. It illustrates the layout of piston pin as well as other features (Srinivasan, 2004). Where; r = crank radius at half of the stroke A = crank angle from the top dead centre l = length of the rod X = position of the piston in relation to the crank centre P = pin of the piston O = crank centre N = pin of the crank a = Pin piston acceleration in the upward direction along the centreline V= piston velocity in the upward direction along the centreline of the cylinder ω= angular velocity of the crank in radian s per second Considering the diagram indicated above, a triangle is formed which is denoted by NOP.

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