- Email: [email protected]
Heat loss to the combustion chamber wall with deposit in D.I. diesel engine: variation of instantaneous heat flux on piston surface with deposit
JSAE Review 23 (2002) 415–421
Heat loss to the combustion chamber wall with deposit in D.I. diesel engine: variation of instantaneous heat flux on piston surface with deposit Yuichi Yamadaa, Masahiko Emia, Hiroyuki Ishiia, Yasuko Suzukia, Shuji Kimurab, Yoshiteru Enomotoa a
Deparetment of Mechanical System Engineering, Musashi Institute of Technology, Tamazutsumi 1-28-1, Setagaya-ku, Tokyo 158-8557, Japan b Nissan Motor Co., Ltd., Natsushima-cho 1, Yokosuka-shi, Kanagawa 237-0061, Japan Received 6 March 2002; received in revised form 17 April 2002
Abstract Adhesion of deposit on the combustion chamber walls affects the state of the heat loss into combustion chamber wall surfaces in the internal combustion engine. In this study, as the first step, the instantaneous surface temperature and the instantaneous heat flux were measured by thin film thermocouples on piston surfaces in the D.I. diesel engine with the adhesion of deposit in order to clarify the effects of deposit. As a result, it is found that the instantaneous surface temperature and heat flux strongly depend on the amount of deposit adhered to the combustion chamber wall surfaces. r 2002 Society of Automotive Engineers of Japan, Inc. and Elsevier Science B.V. All rights reserved.
1. Introduction In order to improve the thermal efficiency of internal combustion engines, it is an effective method to measure the instantaneous temperature on the combustion chamber wall surfaces accurately with the thin film thermocouple (hereafter referred to as ‘‘TFT’’) [1–3], to determine the instantaneous heat flux and to find the state of heat loss at each portion. The adhesion of deposit on the combustion chamber wall surfaces can be considered as one of the factors affecting the state of heat loss of the D.I. diesel engine. Since the fuel is injected directly into the combustion chamber, rich mixture locally exists and a great amount of soot is formed. The soot adheres onto the combustion chamber wall surfaces as deposit, together with the lubricating oil mist and the sulfate formed by burning the sulfur in the fuel. According to previous studies [4,5] by the authors, it was found that the instantaneous surface temperature and heat flux changed with the elapse of time and this change disappeared suddenly. It seems that those variations were caused by deposit adhered to the combustion chamber wall surfaces. However, exact effects of the deposit on the instantaneous surface temperature and heat flux have not been
clarified owing to complicated conditions of deposit. Moreover, in diesel engines generally used, such deposit normally adheres to the wall surfaces. Information about the effects of the deposit on the state of heat loss is also necessary to understand the heat loss in diesel engines. In this paper, as the first report, the authors attempted to clarify the variation of heat loss with the adhesion of deposit. For the observation of this variation, therefore, the instantaneous surface temperature and heat flux were measured in the process of deposit accumulation while keeping the engine operating conditions constant. Furthermore, the authors disassembled the engine and removed the deposit on the piston surfaces after the first experiment, and the second experiment was conducted under the same engine operating conditions again. As a result, it was confirmed that the instantaneous surface temperature and heat flux were varied by the deposit. As the amount of deposit increased, the drop of amplitude, the delay of phase with the maximum value and the decrease in gradient of those curves were observed in the instantaneous surface temperature and heat flux. It was also found that the heat flow into the piston surface became gentler. Nevertheless, the mean heat flux of total strokes, representing the total heat flow
0389-4304/02/$22.00 r 2002 Society of Automotive Engineers of Japan, Inc. and Elsevier Science B.V. All rights reserved. PII: S 0 3 8 9 - 4 3 0 4 ( 0 2 ) 0 0 2 3 3 - 3
JSAE20024661
416
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
in a cycle, remained almost the same. Similar tendencies due to the amount of deposit were observed in remeasurement under the second experiment. It was found that the place with the greatest amount of deposit in the second experiment was the same as the first one.
2. Equipment and method of experiment The Loex-constantan TFT shown in Fig. 1 was used to measure the instantaneous surface temperature and heat flux [1–3]. Low expansion aluminum alloy (hereafter referred to as ‘‘Loex’’), the same material as that of the piston, is used as the body material of Loexconstantan TFT. An insulation layer of about 7.5 mm thickness is formed around the constantan wire of 0.15 mm diameter. The wire is inserted in the center of body material as the core wire. They are pressed and fixed. By using only the copper thin film of about 8.5 mm thickness formed at the top of body, the core wire and the body material are connected to each other to form the hot junction of the Loex-constantan TFT. Approximately 3.5 mm below the top surface, the cold junction is formed by embedding iron and constantan wires of 0.15 mm diameter, which is a J-type thermocouple. The thermoelectromotive force corresponding to the fluctuation of instantaneous surface temperature, which is represented as the temperature difference between the hot and cold junctions of the Loex-constantan TFT, is averaged over 256 cycles. The thermo-electromotive force is converting into the temperature by a high order polynomial of relation between the temperature and the thermoelectromotive force of Loex-constantan thermocouples [6], and adding the cold junction temperature to
Fig. 1. Sectional view of Loex-constantan TFT.
obtain the absolute value of the instantaneous surface temperature. The instantaneous heat flux is calculated with the finite difference method, using Fourier’s thermal conduction differential equation, assuming that the instantaneous surface temperature and the cold junction temperature are the boundary conditions, and taking account of the temperature dependency of the thermophysical properties [7]. The specifications of the single-cylinder D.I. diesel engine used in this study are shown in Table 1. Fig. 2 shows the measuring points, directions of fuel injection and that of swirl. Seven measuring points excluding CS1, where measurement was impossible because of disconnected thermocouples, were located in four Table 1 Engine specification Engine type Bore Stroke Displacement Compression ratio Valve arrangement Swirl ratio Injection pump Injection pressure Nozzle type
Single cylinder direct injection 85.0 mm 86.0 mm 0.488 l 14.8:1 OHC 2.85 Bosch type VE 90 MPa (Np=2200 rpm) 5 holes, + 0.22 mm
Fig. 2. Measuring points at cavity side.
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
directions so that the area of the fuel spray impinging is avoided. In order to observe the variation of the deposit exclusively, the engine operating conditions were set as follows. The engine speed was kept constant at 1200 rpm with the full load, and the ignition timing was kept at the TDC. Light oil with the cetane number of 58 was used as the test fuel. The oil temperature and coolant temperature during measurement were controlled to 36371 and 35371 K, respectively. The first measurement was conducted 14 min after starting the engine when the operating conditions were stabilized. The second measurement was conducted about 60 min after the first measurement, and subsequent measurements were carried out every 30 min up to 270 min. The series of those measurements is referred to as experiment 1. The authors disassembled the engine and the deposit on the piston surface was removed after experiment 1. After that, the re-experiment (experiment 2) was conducted under the same engine operating conditions. The first measurement was conducted 30 min after starting the engine, and subsequent measurements were
417
carried out every 30 min up to 330 min. Experiment 1 has nine measurements and experiment 2 has twelve measurements in all.
3. Results Fig. 3 shows the conditions of deposit adhered onto the piston surface. The directions of fuel injection and swirl are shown together with the measuring points at the cavity side. The amount of deposit at each portion was confirmed by means of visual observation after the experiments and represented by the shade of colors. In the five portions where the fuel spray was expected to impinge, great amounts of deposit adhered, and the traces of separation of deposit were found. A large amount of deposit was found over a wide area closer to the fuel injection nozzle. As regards the measuring points, the greatest amount of deposit was observed at CS3 and relatively great amount of deposit was found at CS4 and CS5. However, only a little amount of deposit was observed at CS7 and CS8. In addition, no trace of separation of deposit was found at any measuring point.
Fig. 3. Condition of deposit on the pison surface.
418
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
Fig. 4. Variation of the instantaneous surface temperature at greater and lesser amount of deposit.
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
Fig. 5. Variation of the instantaneous heat flux at greater and lesser amount of deposit.
419
420
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
Fig. 6. Transition of mean heat flux.
It seems that a greater amount of deposit adhered in experiment 2 since experiment time was longer than experiment 1. Fig. 4 shows the variation of the instantaneous surface temperature difference between the hot junction and the cold junction at CS3 and CS8.There was a great amount of deposit at CS3 and a small amount at CS8. Results of experiment 1 are shown in part (a), and those of experiment 2 are shown in part (b). At CS8, there was no variation of the instantaneous surface temperature in each measurement. At CS3 with large amount of deposit, the amplitude decreased, the phase of appearance of the maximum value delayed and the gradient of the temperature curve became less steep with the elapse of time. In experiment 1, there was a recovery that the appearance of the maximum value was realized earlier and the once decreased magnitude was approaching the original level again during the period from 120 to 180 min. In experiment 2, the recovery was found twice, namely in the periods from 90 to 120 min and from 270 to 330 min. The reason for the recovery is considered to be decrease of the amount of deposit in those periods. Since the recovery occurred twice in experiment 2, such recovery is thought to take place repeatedly in a long time engine operation. Furthermore, the recovery in each experiment was observed at the same elapsed time after engine start. It can be concluded that the process in which the deposit adheres on the surface is almost the same if the engine operating condition is the same. Fig. 5 shows the variation of the instantaneous heat flux at CS3 and CS8. Results of experiment 1 are shown in part (a), and those of experiment 2 are shown in part (b). At CS3, the amplitude decreased, the phase with the maximum value was delayed and gradient of the instantaneous heat flux became gentle, as the amount of deposit increased with the elapse of time. On the
other hand, at CS8 there was no variation of the instantaneous heat flux in each measurement. A similar tendency was found for the other measuring points, whose results are not shown in this paper. Fig. 6 shows the transition of the mean heat flux during total strokes at each measuring point. The mean heat flux, representing the total heat flow in a cycle, tended to become smaller with the elapse of time at every measuring point. However no significant difference because of the amount of deposit, which differs at each measuring point, was observed. In comparison with experiment 1, the instantaneous surface temperature and heat flux in experiment 2 had a large amplitude and slightly early rise, and the mean heat flux in experiment 2 was slightly larger. Because the ignition timing of experiment 2 was BTDC 31, these differences appeared. This relationship between the ignition timing and the variations of the instantaneous surface temperature and heat flux have been clarified in the past [8].
4. Conclusions This study is the first report to clarify the variation in the state of heat loss with the adhesion of deposit. The instantaneous surface temperature and heat flux were measured at seven points on the piston cavity side during the process of deposit accumulation. The remeasurement was conducted under the same engine operating conditions after the deposit on the piston surface was removed. The results show that the variation of instantaneous surface temperature and heat flux was caused by the amount of deposit adhered. The summary of results is shown below. (1) At points where relatively little amount of deposit was found, variations of instantaneous surface
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
temperature and heat flux measured over a long period are practically absent. (2) At points where a large amount of deposit was found, the amplitude decreases, the phase with the maximum value is delayed and the gradient of the curve becomes less in the instantaneous surface temperature and heat flux. (3) The mean heat flux of total strokes remains almost the same regardless of the amount of deposit. (4) The place with a large amount of deposit is the same when the engine operating conditions were the same. It is necessary to measure the quantitative amount of deposit, the state of deposit and thermophysical properties etc. in order to gain greater information on these phenomena.
References [1] Y. Enomoto, S. Furuhama, Study on thin film thermocouple for measuring instantaneous temperature on surface of combustion chamber wall in internal combustion engine, Bull. JSME 28 (235) (1985) 108–116.
421
[2] Y. Enomoto, S. Furuhama, Study on thin film thermocouple for measuring instantaneous temperature on surface of combustion chamber wall in internal combustion engine—2nd report study on thin film thermocouples embedded in combustion chamber wall, Bull. JSME 29 (256) (1986) 3434–3441. [3] Y. Enomoto, et al., Heat loss to combustion chamber wall of 4stroke gasoline engine—1st report heat loss to piston and cylinder, Bull. JSME 28 (238) (1985) 647–655. [4] H. Nagano, et al., Measurement of instantaneous wall surface temperatures on cavity edge in a D.I. diesel engine (in Japanese with English summary), Proc. JSME Ser. 3 (940–30) (1994) 233–235. [5] Y. Enomoto, et al., Measurement of instantaneous surface temperatures on fuel spray impingement points at cavity in a D.I. diesel engine (in Japanese with English summary), Proc. JSME Ser. 3 (940–30) (1994) 236–238. [6] K. Adachi, et al., Study on improvement of accuracy in analysis of instantaneous heat flux flowing into ceramic combustion chamber wall surface—examination in the conversion method from thermoelectromotive force to temperature (in Japanese with English summary), Proc. JSME Ser. 3 (97–01) (1997) 41–42. [7] Y. Enomoto, et al., Study on analysis of instantaneous heat flux flowing into the combustion chamber wall of an internal combustion engine—examination in the case of consideration of heat storage term and the temperature dependency of the thermocouple’s thermophysical properties, JSME Int. J. Ser. 235 (4) (1992) 608–615. [8] T. Uchimi, et al., Heat loss to combustion chamber wall of D.I. diesel engine—1st report: heat loss tendency to piston surface—(in Japanese with English summary), Proc. JSAE (69–98) (1998) 17–20.
Heat loss to the combustion chamber wall with deposit in D.I. diesel engine: variation of instantaneous heat flux on piston surface with deposit Yuichi Yamadaa, Masahiko Emia, Hiroyuki Ishiia, Yasuko Suzukia, Shuji Kimurab, Yoshiteru Enomotoa a
Deparetment of Mechanical System Engineering, Musashi Institute of Technology, Tamazutsumi 1-28-1, Setagaya-ku, Tokyo 158-8557, Japan b Nissan Motor Co., Ltd., Natsushima-cho 1, Yokosuka-shi, Kanagawa 237-0061, Japan Received 6 March 2002; received in revised form 17 April 2002
Abstract Adhesion of deposit on the combustion chamber walls affects the state of the heat loss into combustion chamber wall surfaces in the internal combustion engine. In this study, as the first step, the instantaneous surface temperature and the instantaneous heat flux were measured by thin film thermocouples on piston surfaces in the D.I. diesel engine with the adhesion of deposit in order to clarify the effects of deposit. As a result, it is found that the instantaneous surface temperature and heat flux strongly depend on the amount of deposit adhered to the combustion chamber wall surfaces. r 2002 Society of Automotive Engineers of Japan, Inc. and Elsevier Science B.V. All rights reserved.
1. Introduction In order to improve the thermal efficiency of internal combustion engines, it is an effective method to measure the instantaneous temperature on the combustion chamber wall surfaces accurately with the thin film thermocouple (hereafter referred to as ‘‘TFT’’) [1–3], to determine the instantaneous heat flux and to find the state of heat loss at each portion. The adhesion of deposit on the combustion chamber wall surfaces can be considered as one of the factors affecting the state of heat loss of the D.I. diesel engine. Since the fuel is injected directly into the combustion chamber, rich mixture locally exists and a great amount of soot is formed. The soot adheres onto the combustion chamber wall surfaces as deposit, together with the lubricating oil mist and the sulfate formed by burning the sulfur in the fuel. According to previous studies [4,5] by the authors, it was found that the instantaneous surface temperature and heat flux changed with the elapse of time and this change disappeared suddenly. It seems that those variations were caused by deposit adhered to the combustion chamber wall surfaces. However, exact effects of the deposit on the instantaneous surface temperature and heat flux have not been
clarified owing to complicated conditions of deposit. Moreover, in diesel engines generally used, such deposit normally adheres to the wall surfaces. Information about the effects of the deposit on the state of heat loss is also necessary to understand the heat loss in diesel engines. In this paper, as the first report, the authors attempted to clarify the variation of heat loss with the adhesion of deposit. For the observation of this variation, therefore, the instantaneous surface temperature and heat flux were measured in the process of deposit accumulation while keeping the engine operating conditions constant. Furthermore, the authors disassembled the engine and removed the deposit on the piston surfaces after the first experiment, and the second experiment was conducted under the same engine operating conditions again. As a result, it was confirmed that the instantaneous surface temperature and heat flux were varied by the deposit. As the amount of deposit increased, the drop of amplitude, the delay of phase with the maximum value and the decrease in gradient of those curves were observed in the instantaneous surface temperature and heat flux. It was also found that the heat flow into the piston surface became gentler. Nevertheless, the mean heat flux of total strokes, representing the total heat flow
0389-4304/02/$22.00 r 2002 Society of Automotive Engineers of Japan, Inc. and Elsevier Science B.V. All rights reserved. PII: S 0 3 8 9 - 4 3 0 4 ( 0 2 ) 0 0 2 3 3 - 3
JSAE20024661
416
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
in a cycle, remained almost the same. Similar tendencies due to the amount of deposit were observed in remeasurement under the second experiment. It was found that the place with the greatest amount of deposit in the second experiment was the same as the first one.
2. Equipment and method of experiment The Loex-constantan TFT shown in Fig. 1 was used to measure the instantaneous surface temperature and heat flux [1–3]. Low expansion aluminum alloy (hereafter referred to as ‘‘Loex’’), the same material as that of the piston, is used as the body material of Loexconstantan TFT. An insulation layer of about 7.5 mm thickness is formed around the constantan wire of 0.15 mm diameter. The wire is inserted in the center of body material as the core wire. They are pressed and fixed. By using only the copper thin film of about 8.5 mm thickness formed at the top of body, the core wire and the body material are connected to each other to form the hot junction of the Loex-constantan TFT. Approximately 3.5 mm below the top surface, the cold junction is formed by embedding iron and constantan wires of 0.15 mm diameter, which is a J-type thermocouple. The thermoelectromotive force corresponding to the fluctuation of instantaneous surface temperature, which is represented as the temperature difference between the hot and cold junctions of the Loex-constantan TFT, is averaged over 256 cycles. The thermo-electromotive force is converting into the temperature by a high order polynomial of relation between the temperature and the thermoelectromotive force of Loex-constantan thermocouples [6], and adding the cold junction temperature to
Fig. 1. Sectional view of Loex-constantan TFT.
obtain the absolute value of the instantaneous surface temperature. The instantaneous heat flux is calculated with the finite difference method, using Fourier’s thermal conduction differential equation, assuming that the instantaneous surface temperature and the cold junction temperature are the boundary conditions, and taking account of the temperature dependency of the thermophysical properties [7]. The specifications of the single-cylinder D.I. diesel engine used in this study are shown in Table 1. Fig. 2 shows the measuring points, directions of fuel injection and that of swirl. Seven measuring points excluding CS1, where measurement was impossible because of disconnected thermocouples, were located in four Table 1 Engine specification Engine type Bore Stroke Displacement Compression ratio Valve arrangement Swirl ratio Injection pump Injection pressure Nozzle type
Single cylinder direct injection 85.0 mm 86.0 mm 0.488 l 14.8:1 OHC 2.85 Bosch type VE 90 MPa (Np=2200 rpm) 5 holes, + 0.22 mm
Fig. 2. Measuring points at cavity side.
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
directions so that the area of the fuel spray impinging is avoided. In order to observe the variation of the deposit exclusively, the engine operating conditions were set as follows. The engine speed was kept constant at 1200 rpm with the full load, and the ignition timing was kept at the TDC. Light oil with the cetane number of 58 was used as the test fuel. The oil temperature and coolant temperature during measurement were controlled to 36371 and 35371 K, respectively. The first measurement was conducted 14 min after starting the engine when the operating conditions were stabilized. The second measurement was conducted about 60 min after the first measurement, and subsequent measurements were carried out every 30 min up to 270 min. The series of those measurements is referred to as experiment 1. The authors disassembled the engine and the deposit on the piston surface was removed after experiment 1. After that, the re-experiment (experiment 2) was conducted under the same engine operating conditions. The first measurement was conducted 30 min after starting the engine, and subsequent measurements were
417
carried out every 30 min up to 330 min. Experiment 1 has nine measurements and experiment 2 has twelve measurements in all.
3. Results Fig. 3 shows the conditions of deposit adhered onto the piston surface. The directions of fuel injection and swirl are shown together with the measuring points at the cavity side. The amount of deposit at each portion was confirmed by means of visual observation after the experiments and represented by the shade of colors. In the five portions where the fuel spray was expected to impinge, great amounts of deposit adhered, and the traces of separation of deposit were found. A large amount of deposit was found over a wide area closer to the fuel injection nozzle. As regards the measuring points, the greatest amount of deposit was observed at CS3 and relatively great amount of deposit was found at CS4 and CS5. However, only a little amount of deposit was observed at CS7 and CS8. In addition, no trace of separation of deposit was found at any measuring point.
Fig. 3. Condition of deposit on the pison surface.
418
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
Fig. 4. Variation of the instantaneous surface temperature at greater and lesser amount of deposit.
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
Fig. 5. Variation of the instantaneous heat flux at greater and lesser amount of deposit.
419
420
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
Fig. 6. Transition of mean heat flux.
It seems that a greater amount of deposit adhered in experiment 2 since experiment time was longer than experiment 1. Fig. 4 shows the variation of the instantaneous surface temperature difference between the hot junction and the cold junction at CS3 and CS8.There was a great amount of deposit at CS3 and a small amount at CS8. Results of experiment 1 are shown in part (a), and those of experiment 2 are shown in part (b). At CS8, there was no variation of the instantaneous surface temperature in each measurement. At CS3 with large amount of deposit, the amplitude decreased, the phase of appearance of the maximum value delayed and the gradient of the temperature curve became less steep with the elapse of time. In experiment 1, there was a recovery that the appearance of the maximum value was realized earlier and the once decreased magnitude was approaching the original level again during the period from 120 to 180 min. In experiment 2, the recovery was found twice, namely in the periods from 90 to 120 min and from 270 to 330 min. The reason for the recovery is considered to be decrease of the amount of deposit in those periods. Since the recovery occurred twice in experiment 2, such recovery is thought to take place repeatedly in a long time engine operation. Furthermore, the recovery in each experiment was observed at the same elapsed time after engine start. It can be concluded that the process in which the deposit adheres on the surface is almost the same if the engine operating condition is the same. Fig. 5 shows the variation of the instantaneous heat flux at CS3 and CS8. Results of experiment 1 are shown in part (a), and those of experiment 2 are shown in part (b). At CS3, the amplitude decreased, the phase with the maximum value was delayed and gradient of the instantaneous heat flux became gentle, as the amount of deposit increased with the elapse of time. On the
other hand, at CS8 there was no variation of the instantaneous heat flux in each measurement. A similar tendency was found for the other measuring points, whose results are not shown in this paper. Fig. 6 shows the transition of the mean heat flux during total strokes at each measuring point. The mean heat flux, representing the total heat flow in a cycle, tended to become smaller with the elapse of time at every measuring point. However no significant difference because of the amount of deposit, which differs at each measuring point, was observed. In comparison with experiment 1, the instantaneous surface temperature and heat flux in experiment 2 had a large amplitude and slightly early rise, and the mean heat flux in experiment 2 was slightly larger. Because the ignition timing of experiment 2 was BTDC 31, these differences appeared. This relationship between the ignition timing and the variations of the instantaneous surface temperature and heat flux have been clarified in the past [8].
4. Conclusions This study is the first report to clarify the variation in the state of heat loss with the adhesion of deposit. The instantaneous surface temperature and heat flux were measured at seven points on the piston cavity side during the process of deposit accumulation. The remeasurement was conducted under the same engine operating conditions after the deposit on the piston surface was removed. The results show that the variation of instantaneous surface temperature and heat flux was caused by the amount of deposit adhered. The summary of results is shown below. (1) At points where relatively little amount of deposit was found, variations of instantaneous surface
Y. Yamada et al. / JSAE Review 23 (2002) 415–421
temperature and heat flux measured over a long period are practically absent. (2) At points where a large amount of deposit was found, the amplitude decreases, the phase with the maximum value is delayed and the gradient of the curve becomes less in the instantaneous surface temperature and heat flux. (3) The mean heat flux of total strokes remains almost the same regardless of the amount of deposit. (4) The place with a large amount of deposit is the same when the engine operating conditions were the same. It is necessary to measure the quantitative amount of deposit, the state of deposit and thermophysical properties etc. in order to gain greater information on these phenomena.
References [1] Y. Enomoto, S. Furuhama, Study on thin film thermocouple for measuring instantaneous temperature on surface of combustion chamber wall in internal combustion engine, Bull. JSME 28 (235) (1985) 108–116.
421
[2] Y. Enomoto, S. Furuhama, Study on thin film thermocouple for measuring instantaneous temperature on surface of combustion chamber wall in internal combustion engine—2nd report study on thin film thermocouples embedded in combustion chamber wall, Bull. JSME 29 (256) (1986) 3434–3441. [3] Y. Enomoto, et al., Heat loss to combustion chamber wall of 4stroke gasoline engine—1st report heat loss to piston and cylinder, Bull. JSME 28 (238) (1985) 647–655. [4] H. Nagano, et al., Measurement of instantaneous wall surface temperatures on cavity edge in a D.I. diesel engine (in Japanese with English summary), Proc. JSME Ser. 3 (940–30) (1994) 233–235. [5] Y. Enomoto, et al., Measurement of instantaneous surface temperatures on fuel spray impingement points at cavity in a D.I. diesel engine (in Japanese with English summary), Proc. JSME Ser. 3 (940–30) (1994) 236–238. [6] K. Adachi, et al., Study on improvement of accuracy in analysis of instantaneous heat flux flowing into ceramic combustion chamber wall surface—examination in the conversion method from thermoelectromotive force to temperature (in Japanese with English summary), Proc. JSME Ser. 3 (97–01) (1997) 41–42. [7] Y. Enomoto, et al., Study on analysis of instantaneous heat flux flowing into the combustion chamber wall of an internal combustion engine—examination in the case of consideration of heat storage term and the temperature dependency of the thermocouple’s thermophysical properties, JSME Int. J. Ser. 235 (4) (1992) 608–615. [8] T. Uchimi, et al., Heat loss to combustion chamber wall of D.I. diesel engine—1st report: heat loss tendency to piston surface—(in Japanese with English summary), Proc. JSAE (69–98) (1998) 17–20.