Pega Hrnjak publications per year

The chart shows the history of publications by Pega Hrnjak between 1990 and 2025, highlighting the no. of papers published in each year and offering an overview of the publication velocity of this scholar. Pega Hrnjak published across 36 years, from 1990 to 2025, averaging 14.8 papers a year. Output peaked at 40 publications in 2014. 4 of the 534 publications appeared in the last two years.

No. of publications

10 20 30 40

1990 2025

534 publications in total across all disciplines

View publications per year as a table

Pega Hrnjak: publications per year, 1990 to 2025
Year	Publications
1990	1
1991	0
1992	0
1993	0
1994	0
1995	0
1996	1
1997	3
1998	9
1999	14
2000	12
2001	16
2002	25
2003	19
2004	11
2005	8
2006	23
2007	8
2008	13
2009	17
2010	22
2011	11
2012	33
2013	21
2014	40
2015	21
2016	35
2017	26
2018	37
2019	40
2020	20
2021	29
2022	9
2023	6
2024	2
2025	2
Total	534

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Pega Hrnjak publication distribution in Mechanical and Aerospace Engineering in 2026

The chart shows the distribution of publications by all Research.com ranked scientists in the field of Mechanical and Aerospace Engineering in 2026. The highlighted bar marks where Pega Hrnjak sits on this spectrum.

No. of scientists

50 100 150

47–56 publications 659+

This scientist: 519 publications — 94th percentile

94% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 659 publications or more.

View publications distribution as a table

Number of Mechanical and Aerospace Engineering scientists by publication count, Research.com 2026 ranking edition. Based on 3,445 ranked scientists.
Publications	Scientists	This scientist
47–56	10
57–66	23
67–76	32
77–86	62
87–96	67
97–106	91
107–116	113
117–126	115
127–136	130
137–146	140
147–156	155
157–166	132
167–176	133
177–186	130
187–196	140
197–206	115
207–216	125
217–226	117
227–236	99
237–246	92
247–256	100
257–266	95
267–276	88
277–286	77
287–296	74
297–306	74
307–316	62
317–326	70
327–336	59
337–346	58
347–356	45
357–366	44
367–376	36
377–386	41
387–396	32
397–406	23
407–416	28
417–426	27
427–436	25
437–446	23
447–456	23
457–466	20
467–476	12
477–486	24
487–496	18
497–506	12
507–516	13
517–526	21	519
527–536	12
537–546	8
547–556	16
557–566	3
567–576	11
577–586	6
587–596	5
597–606	6
607–616	7
617–626	7
627–636	10
637–646	4
647–656	3
657–658	2
659+	100

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Pega Hrnjak D-index placement in Mechanical and Aerospace Engineering in 2026

The chart shows the D-index (discipline H-index) distribution of Mechanical and Aerospace Engineering scientists ranked by Research.com in 2026. The highlighted bar marks where Pega Hrnjak sits on this spectrum.

No. of scientists

50 100 150

30 D-Index 93+

This scientist: 42 D-Index — 49th percentile

49% of scientists in this discipline score the same or lower.

The last bar groups every scientist with 93 D-Index or more.

View D-Index distribution as a table

Number of Mechanical and Aerospace Engineering scientists by D-index, Research.com 2026 ranking edition. Based on 3,445 ranked scientists.
D-Index	Scientists	This scientist
30	83
31	113
32	144
33	153
34	189
35	158
36	139
37	127
38	130
39	126
40	104
41	100
42	107	42
43	101
44	103
45	79
46	88
47	70
48	83
49	44
50	64
51	56
52	50
53	48
54	58
55	52
56	48
57	42
58	34
59	42
60	37
61	42
62	44
63	22
64	33
65	29
66	23
67	29
68	24
69	19
70	34
71	26
72	19
73	18
74	19
75	14
76	19
77	8
78	18
79	16
80	12
81	17
82	11
83	16
84	7
85	9
86	8
87	6
88	6
89	7
90	10
91	4
92	4
93+	100

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Best Publications

Experimental validation of a prototype ejector designed to reduce throttling losses encountered in transcritical R744 system operation

Stefan Elbel;Pega Hrnjak

550
Citations
Frost, defrost, and refrost and its impact on the air-side thermal-hydraulic performance of louvered-fin, flat-tube heat exchangers

Y. Xia;Y. Zhong;P.S. Hrnjak;A.M. Jacobi

214
Citations
R-744 gas cooler model development and validation

Jian Min Yin;Clark W. Bullard;Predrag S. Hrnjak

193
Citations
CO2 and R410A flow boiling heat transfer, pressure drop, and flow pattern at low temperatures in a horizontal smooth tube

C.Y. Park;P.S. Hrnjak

189
Citations
Experimental and numerical study on microchannel and round-tube condensers in a R410A residential air-conditioning system

Chang Yong Park;Pega Hrnjak

147
Citations
Single phase pressure drop in microchannels

Predrag Stojan Hrnjak;Xiao Tu

137
Citations
Flash gas bypass for improving the performance of transcritical R744 systems that use microchannel evaporators

Stefan Elbel;Predrag Stojan Hrnjak

129
Citations
Contribution of Internal Heat Exchanger to Transcritical R-744 Cycle Performance

D. E. Boewe;C. W. Bullard;J. M. Yin;P. S. Hrnjak

126
Citations
Microchannel heat exchangers for charge minimization in air-cooled ammonia condensers and chillers

Pega Hrnjak;Andy D. Litch

121
Citations
Flash gas bypass in mobile air conditioning system with R134a

Hanfei Tuo;Predrag Stojan Hrnjak

119
Citations
Experimental results of transcritical CO2 heat pump for residential application

M. R. Richter;S. M. Song;J. M. Yin;M. H. Kim

109
Citations
Experimental investigation on two-phase flow boiling heat transfer of five refrigerants in horizontal small tubes of 0.5, 1.5 and 3.0 mm inner diameters

Jong Taek Oh;Agus Sunjarianto Pamitran;Kwang Il Choi;Pega Hrnjak

108
Citations
CO2 flow condensation heat transfer and pressure drop in multi-port microchannels at low temperatures

Chang Yong Park;Predrag Stojan Hrnjak

106
Citations
Effect of the header pressure drop induced flow maldistribution on the microchannel evaporator performance

Hanfei Tuo;Predrag Stojan Hrnjak;Predrag Stojan Hrnjak

103
Citations
Effect of the condenser subcooling on the performance of vapor compression systems

Gustavo Pottker;Predrag Stojan Hrnjak

103
Citations
Characteristics of two-phase flow pattern transitions and pressure drop of five refrigerants in horizontal circular small tubes

Agus Sunjarianto Pamitran;Kwang Il Choi;Jong Taek Oh;Pega Hrnjak

98
Citations
Experiment and visualization on R134a upward flow in the vertical header of microchannel heat exchanger and its effect on distribution

Yang Zou;Predrag Stojan Hrnjak;Predrag Stojan Hrnjak

95
Citations
Experimental investigation of the effect of condenser subcooling in R134a and R1234yf air-conditioning systems with and without internal heat exchanger

Gustavo Pottker;Pega Hrnjak

94
Citations
Air-side performance evaluation of three types of heat exchangers in dry, wet and periodic frosting conditions

Ping Zhang;Ping Zhang;Predrag Stojan Hrnjak

89
Citations
Ejector Refrigeration: An Overview of Historical and Present Developments with an Emphasis on Air-Conditioning Applications

Stefan Elbel;Predrag Hrnjak

87
Citations

Frequent Co-Authors

Anthony M. Jacobi University of Illinois at Urbana-Champaign

Andrew G. Alleyne University of Minnesota

Mark A. Shannon University of Illinois at Urbana-Champaign

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Exploring the different types of counseling degrees also offers insight into how engineering graduates might integrate counseling or leadership roles in technical industries, emphasizing the value of a multidisciplinary education.

D-Index	Scientists	This scientist
30	83
31	113
32	144
33	153
34	189
35	158
36	139
37	127
38	130
39	126
40	104
41	100
42	107	42
43	101
44	103
45	79
46	88
47	70
48	83
49	44
50	64
51	56
52	50
53	48
54	58
55	52
56	48
57	42
58	34
59	42
60	37
61	42
62	44
63	22
64	33
65	29
66	23
67	29
68	24
69	19
70	34
71	26
72	19
73	18
74	19
75	14
76	19
77	8
78	18
79	16
80	12
81	17
82	11
83	16
84	7
85	9
86	8
87	6
88	6
89	7
90	10
91	4
92	4
93+	100

D-Index	Scientists	This scientist
30	83
31	113
32	144
33	153
34	189
35	158
36	139
37	127
38	130
39	126
40	104
41	100
42	107	42
43	101
44	103
45	79
46	88
47	70
48	83
49	44
50	64
51	56
52	50
53	48
54	58
55	52
56	48
57	42
58	34
59	42
60	37
61	42
62	44
63	22
64	33
65	29
66	23
67	29
68	24
69	19
70	34
71	26
72	19
73	18
74	19
75	14
76	19
77	8
78	18
79	16
80	12
81	17
82	11
83	16
84	7
85	9
86	8
87	6
88	6
89	7
90	10
91	4
92	4
93+	100

Pega Hrnjak

D-Index & Metrics

Pega Hrnjak publications per year

Pega Hrnjak publication distribution in Mechanical and Aerospace Engineering in 2026

Pega Hrnjak D-index placement in Mechanical and Aerospace Engineering in 2026

Best Publications

Experimental validation of a prototype ejector designed to reduce throttling losses encountered in transcritical R744 system operation

Frost, defrost, and refrost and its impact on the air-side thermal-hydraulic performance of louvered-fin, flat-tube heat exchangers

R-744 gas cooler model development and validation

CO2 and R410A flow boiling heat transfer, pressure drop, and flow pattern at low temperatures in a horizontal smooth tube

Experimental and numerical study on microchannel and round-tube condensers in a R410A residential air-conditioning system

Single phase pressure drop in microchannels

Flash gas bypass for improving the performance of transcritical R744 systems that use microchannel evaporators

Contribution of Internal Heat Exchanger to Transcritical R-744 Cycle Performance

Microchannel heat exchangers for charge minimization in air-cooled ammonia condensers and chillers

Flash gas bypass in mobile air conditioning system with R134a

Experimental results of transcritical CO2 heat pump for residential application

Experimental investigation on two-phase flow boiling heat transfer of five refrigerants in horizontal small tubes of 0.5, 1.5 and 3.0 mm inner diameters

CO2 flow condensation heat transfer and pressure drop in multi-port microchannels at low temperatures

Effect of the header pressure drop induced flow maldistribution on the microchannel evaporator performance

Effect of the condenser subcooling on the performance of vapor compression systems

Characteristics of two-phase flow pattern transitions and pressure drop of five refrigerants in horizontal circular small tubes

Experiment and visualization on R134a upward flow in the vertical header of microchannel heat exchanger and its effect on distribution

Experimental investigation of the effect of condenser subcooling in R134a and R1234yf air-conditioning systems with and without internal heat exchanger

Air-side performance evaluation of three types of heat exchangers in dry, wet and periodic frosting conditions

Ejector Refrigeration: An Overview of Historical and Present Developments with an Emphasis on Air-Conditioning Applications

Frequent Co-Authors

Related Online Degrees & Career Pathways

Best Scientists Citing Pega Hrnjak

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D-Index	Scientists	This scientist
30	83
31	113
32	144
33	153
34	189
35	158
36	139
37	127
38	130
39	126
40	104
41	100
42	107	42
43	101
44	103
45	79
46	88
47	70
48	83
49	44
50	64
51	56
52	50
53	48
54	58
55	52
56	48
57	42
58	34
59	42
60	37
61	42
62	44
63	22
64	33
65	29
66	23
67	29
68	24
69	19
70	34
71	26
72	19
73	18
74	19
75	14
76	19
77	8
78	18
79	16
80	12
81	17
82	11
83	16
84	7
85	9
86	8
87	6
88	6
89	7
90	10
91	4
92	4
93+	100